diff --git a/rules.neon b/rules.neon
index 63eaa60f..f38ecafe 100644
--- a/rules.neon
+++ b/rules.neon
@@ -18,6 +18,7 @@ rules:
 	- PHPStan\Rules\Doctrine\ORM\MagicRepositoryMethodCallRule
 	- PHPStan\Rules\Doctrine\ORM\RepositoryMethodCallRule
 	- PHPStan\Rules\Doctrine\ORM\EntityColumnRule
+	- PHPStan\Rules\Doctrine\ORM\EntityRelationRule
 
 services:
 	-
diff --git a/src/Rules/Doctrine/ORM/EntityRelationRule.php b/src/Rules/Doctrine/ORM/EntityRelationRule.php
new file mode 100644
index 00000000..0af79c85
--- /dev/null
+++ b/src/Rules/Doctrine/ORM/EntityRelationRule.php
@@ -0,0 +1,100 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MissingPropertyFromReflectionException;
+use PHPStan\Rules\Rule;
+use PHPStan\Type\Doctrine\ObjectMetadataResolver;
+use PHPStan\Type\IterableType;
+use PHPStan\Type\MixedType;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\TypeCombinator;
+use PHPStan\Type\VerbosityLevel;
+use function sprintf;
+
+class EntityRelationRule implements Rule
+{
+
+	/** @var \PHPStan\Type\Doctrine\ObjectMetadataResolver */
+	private $objectMetadataResolver;
+
+	public function __construct(ObjectMetadataResolver $objectMetadataResolver)
+	{
+		$this->objectMetadataResolver = $objectMetadataResolver;
+	}
+
+	public function getNodeType(): string
+	{
+		return Node\Stmt\PropertyProperty::class;
+	}
+
+	/**
+	 * @param \PhpParser\Node\Stmt\PropertyProperty $node
+	 * @param \PHPStan\Analyser\Scope $scope
+	 * @return string[]
+	 */
+	public function processNode(Node $node, Scope $scope): array
+	{
+		$class = $scope->getClassReflection();
+		if ($class === null) {
+			return [];
+		}
+
+		$objectManager = $this->objectMetadataResolver->getObjectManager();
+		if ($objectManager === null) {
+			return [];
+		}
+
+		$className = $class->getName();
+		if ($objectManager->getMetadataFactory()->isTransient($className)) {
+			return [];
+		}
+
+		/** @var \Doctrine\ORM\Mapping\ClassMetadataInfo $metadata */
+		$metadata = $objectManager->getClassMetadata($className);
+		$classMetadataInfo = 'Doctrine\ORM\Mapping\ClassMetadataInfo';
+		if (!$metadata instanceof $classMetadataInfo) {
+			return [];
+		}
+
+		$propertyName = (string) $node->name;
+		try {
+			$property = $class->getNativeProperty($propertyName);
+		} catch (MissingPropertyFromReflectionException $e) {
+			return [];
+		}
+
+		if (!isset($metadata->associationMappings[$propertyName])) {
+			return [];
+		}
+		$associationMapping = $metadata->associationMappings[$propertyName];
+
+		$columnType = null;
+		if ((bool) ($associationMapping['type'] & 3)) { // ClassMetadataInfo::TO_ONE
+			$columnType = new ObjectType($associationMapping['targetEntity']);
+			if ($associationMapping['joinColumns'][0]['nullable'] ?? true) {
+				$columnType = TypeCombinator::addNull($columnType);
+			}
+		} elseif ((bool) ($associationMapping['type'] & 12)) { // ClassMetadataInfo::TO_MANY
+			$columnType = TypeCombinator::intersect(
+				new ObjectType('Doctrine\Common\Collections\Collection'),
+				new IterableType(new MixedType(), new ObjectType($associationMapping['targetEntity']))
+			);
+		}
+
+		$errors = [];
+		if ($columnType !== null) {
+			if (!$property->getWritableType()->isSuperTypeOf($columnType)->yes()) {
+				$errors[] = sprintf('Database can contain %s but property expects %s.', $columnType->describe(VerbosityLevel::typeOnly()), $property->getWritableType()->describe(VerbosityLevel::typeOnly()));
+			}
+			if (!$columnType->isSuperTypeOf($property->getReadableType())->yes()) {
+				$errors[] = sprintf('Property can contain %s but database expects %s.', $property->getReadableType()->describe(VerbosityLevel::typeOnly()), $columnType->describe(VerbosityLevel::typeOnly()));
+			}
+		}
+
+		return $errors;
+	}
+
+}
diff --git a/tests/Rules/Doctrine/ORM/EntityRelationRuleTest.php b/tests/Rules/Doctrine/ORM/EntityRelationRuleTest.php
new file mode 100644
index 00000000..e2078842
--- /dev/null
+++ b/tests/Rules/Doctrine/ORM/EntityRelationRuleTest.php
@@ -0,0 +1,113 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use Iterator;
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+use PHPStan\Type\Doctrine\ObjectMetadataResolver;
+
+class EntityRelationRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new EntityRelationRule(
+			new ObjectMetadataResolver(__DIR__ . '/entity-manager.php', null)
+		);
+	}
+
+	/**
+	 * @dataProvider ruleProvider
+	 */
+	public function testRule(string $file, array $expectedErrors): void
+	{
+		$this->analyse([$file], $expectedErrors);
+	}
+
+	public function ruleProvider(): Iterator
+	{
+		yield 'nice entity' => [__DIR__ . '/data/EntityWithRelations.php', []];
+
+		yield 'one to one' => [__DIR__ . '/data/EntityWithBrokenOneToOneRelations.php',
+			[
+				[
+					'Property can contain PHPStan\Rules\Doctrine\ORM\AnotherEntity|null but database expects PHPStan\Rules\Doctrine\ORM\AnotherEntity.',
+					31,
+				],
+				[
+					'Database can contain PHPStan\Rules\Doctrine\ORM\AnotherEntity|null but property expects PHPStan\Rules\Doctrine\ORM\AnotherEntity.',
+					37,
+				],
+				[
+					'Database can contain PHPStan\Rules\Doctrine\ORM\AnotherEntity|null but property expects PHPStan\Rules\Doctrine\ORM\MyEntity|null.',
+					50,
+				],
+				[
+					'Property can contain PHPStan\Rules\Doctrine\ORM\MyEntity|null but database expects PHPStan\Rules\Doctrine\ORM\AnotherEntity|null.',
+					50,
+				],
+			]];
+
+		yield 'many to one' => [__DIR__ . '/data/EntityWithBrokenManyToOneRelations.php',
+			[
+				[
+					'Property can contain PHPStan\Rules\Doctrine\ORM\AnotherEntity|null but database expects PHPStan\Rules\Doctrine\ORM\AnotherEntity.',
+					31,
+				],
+				[
+					'Database can contain PHPStan\Rules\Doctrine\ORM\AnotherEntity|null but property expects PHPStan\Rules\Doctrine\ORM\AnotherEntity.',
+					37,
+				],
+				[
+					'Database can contain PHPStan\Rules\Doctrine\ORM\AnotherEntity|null but property expects PHPStan\Rules\Doctrine\ORM\MyEntity|null.',
+					50,
+				],
+				[
+					'Property can contain PHPStan\Rules\Doctrine\ORM\MyEntity|null but database expects PHPStan\Rules\Doctrine\ORM\AnotherEntity|null.',
+					50,
+				],
+			]];
+
+		yield 'one to many' => [__DIR__ . '/data/EntityWithBrokenOneToManyRelations.php',
+			[
+				[
+					'Property can contain iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity> but database expects Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					24,
+				],
+				[
+					'Property can contain Doctrine\Common\Collections\Collection but database expects Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					30,
+				],
+				[
+					'Database can contain Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity> but property expects array<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					36,
+				],
+				[
+					'Property can contain array<PHPStan\Rules\Doctrine\ORM\AnotherEntity> but database expects Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					36,
+				],
+			]];
+
+		yield 'many to many' => [__DIR__ . '/data/EntityWithBrokenManyToManyRelations.php',
+			[
+				[
+					'Property can contain iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity> but database expects Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					24,
+				],
+				[
+					'Property can contain Doctrine\Common\Collections\Collection but database expects Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					30,
+				],
+				[
+					'Database can contain Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity> but property expects array<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					36,
+				],
+				[
+					'Property can contain array<PHPStan\Rules\Doctrine\ORM\AnotherEntity> but database expects Doctrine\Common\Collections\Collection&iterable<PHPStan\Rules\Doctrine\ORM\AnotherEntity>.',
+					36,
+				],
+			]];
+	}
+
+}
diff --git a/tests/Rules/Doctrine/ORM/data/AnotherEntity.php b/tests/Rules/Doctrine/ORM/data/AnotherEntity.php
new file mode 100644
index 00000000..70c91ee8
--- /dev/null
+++ b/tests/Rules/Doctrine/ORM/data/AnotherEntity.php
@@ -0,0 +1,50 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity()
+ */
+class AnotherEntity
+{
+
+	/**
+	 * @ORM\Id()
+	 * @ORM\Column(type="int")
+	 * @var int
+	 */
+	private $id;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\EntityWithRelations")
+	 */
+	private $manyToOne;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\EntityWithBrokenOneToManyRelations")
+	 */
+	private $one;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\EntityWithBrokenOneToManyRelations")
+	 */
+	private $two;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\EntityWithBrokenOneToManyRelations")
+	 */
+	private $three;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\EntityWithBrokenOneToManyRelations")
+	 */
+	private $four;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\EntityWithBrokenOneToManyRelations")
+	 */
+	private $five;
+
+}
diff --git a/tests/Rules/Doctrine/ORM/data/EntityWithBrokenManyToManyRelations.php b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenManyToManyRelations.php
new file mode 100644
index 00000000..dd2e0d78
--- /dev/null
+++ b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenManyToManyRelations.php
@@ -0,0 +1,50 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity()
+ */
+class EntityWithBrokenManyToManyRelations
+{
+
+	/**
+	 * @ORM\Id()
+	 * @ORM\Column(type="int")
+	 * @var int
+	 */
+	private $id;
+
+	/**
+	 * @ORM\ManyToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var iterable<\PHPStan\Rules\Doctrine\ORM\AnotherEntity>
+	 */
+	private $manyToManyWithIterableAnnotation;
+
+	/**
+	 * @ORM\ManyToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \Doctrine\Common\Collections\Collection
+	 */
+	private $manyToManyWithCollectionAnnotation;
+
+	/**
+	 * @ORM\ManyToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity[]
+	 */
+	private $manyToManyWithArrayAnnotation;
+
+	/**
+	 * @ORM\ManyToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \Doctrine\Common\Collections\Collection&iterable<\PHPStan\Rules\Doctrine\ORM\AnotherEntity>
+	 */
+	private $manyToManyWithCorrectAnnotation;
+
+	/**
+	 * @ORM\ManyToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \Doctrine\Common\Collections\Collection|\PHPStan\Rules\Doctrine\ORM\AnotherEntity[]
+	 */
+	private $manyToManyWithCorrectOldStyleAnnotation;
+
+}
diff --git a/tests/Rules/Doctrine/ORM/data/EntityWithBrokenManyToOneRelations.php b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenManyToOneRelations.php
new file mode 100644
index 00000000..c97d4567
--- /dev/null
+++ b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenManyToOneRelations.php
@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity()
+ */
+class EntityWithBrokenManyToOneRelations
+{
+
+	/**
+	 * @ORM\Id()
+	 * @ORM\Column(type="int")
+	 * @var int
+	 */
+	private $id;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity|null
+	 */
+	private $manyToOneNullableBoth;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @ORM\JoinColumn(nullable=false)
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity|null
+	 */
+	private $manyToOneNullableProperty;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity
+	 */
+	private $manyToOneNullableColumn;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @ORM\JoinColumn(nullable=false)
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity
+	 */
+	private $manyToOneNonNullable;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\MyEntity|null
+	 */
+	private $manyToOneWrongClass;
+
+}
diff --git a/tests/Rules/Doctrine/ORM/data/EntityWithBrokenOneToManyRelations.php b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenOneToManyRelations.php
new file mode 100644
index 00000000..421012f0
--- /dev/null
+++ b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenOneToManyRelations.php
@@ -0,0 +1,50 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity()
+ */
+class EntityWithBrokenOneToManyRelations
+{
+
+	/**
+	 * @ORM\Id()
+	 * @ORM\Column(type="int")
+	 * @var int
+	 */
+	private $id;
+
+	/**
+	 * @ORM\OneToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity", mappedBy="one")
+	 * @var iterable<\PHPStan\Rules\Doctrine\ORM\AnotherEntity>
+	 */
+	private $oneToManyWithIterableAnnotation;
+
+	/**
+	 * @ORM\OneToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity", mappedBy="two")
+	 * @var \Doctrine\Common\Collections\Collection
+	 */
+	private $oneToManyWithCollectionAnnotation;
+
+	/**
+	 * @ORM\OneToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity", mappedBy="three")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity[]
+	 */
+	private $oneToManyWithArrayAnnotation;
+
+	/**
+	 * @ORM\OneToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity", mappedBy="four")
+	 * @var \Doctrine\Common\Collections\Collection&iterable<\PHPStan\Rules\Doctrine\ORM\AnotherEntity>
+	 */
+	private $oneToManyWithCorrectAnnotation;
+
+	/**
+	 * @ORM\OneToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity", mappedBy="five")
+	 * @var \Doctrine\Common\Collections\Collection|\PHPStan\Rules\Doctrine\ORM\AnotherEntity[]
+	 */
+	private $oneToManyWithCorrectOldStyleAnnotation;
+
+}
diff --git a/tests/Rules/Doctrine/ORM/data/EntityWithBrokenOneToOneRelations.php b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenOneToOneRelations.php
new file mode 100644
index 00000000..4605e98e
--- /dev/null
+++ b/tests/Rules/Doctrine/ORM/data/EntityWithBrokenOneToOneRelations.php
@@ -0,0 +1,52 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity()
+ */
+class EntityWithBrokenOneToOneRelations
+{
+
+	/**
+	 * @ORM\Id()
+	 * @ORM\Column(type="int")
+	 * @var int
+	 */
+	private $id;
+
+	/**
+	 * @ORM\OneToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity|null
+	 */
+	private $oneToOneNullableBoth;
+
+	/**
+	 * @ORM\OneToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @ORM\JoinColumn(nullable=false)
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity|null
+	 */
+	private $oneToOneNullableProperty;
+
+	/**
+	 * @ORM\OneToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity
+	 */
+	private $oneToOneNullableColumn;
+
+	/**
+	 * @ORM\OneToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @ORM\JoinColumn(nullable=false)
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity
+	 */
+	private $oneToOneNonNullable;
+
+	/**
+	 * @ORM\OneToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\MyEntity|null
+	 */
+	private $oneToOneWrongClass;
+
+}
diff --git a/tests/Rules/Doctrine/ORM/data/EntityWithRelations.php b/tests/Rules/Doctrine/ORM/data/EntityWithRelations.php
new file mode 100644
index 00000000..aee7a879
--- /dev/null
+++ b/tests/Rules/Doctrine/ORM/data/EntityWithRelations.php
@@ -0,0 +1,44 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Doctrine\ORM;
+
+use Doctrine\ORM\Mapping as ORM;
+
+/**
+ * @ORM\Entity()
+ */
+class EntityWithRelations
+{
+
+	/**
+	 * @ORM\Id()
+	 * @ORM\Column(type="int")
+	 * @var int
+	 */
+	private $id;
+
+	/**
+	 * @ORM\OneToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity|null
+	 */
+	private $oneToOne;
+
+	/**
+	 * @ORM\ManyToOne(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \PHPStan\Rules\Doctrine\ORM\AnotherEntity|null
+	 */
+	private $manyToOne;
+
+	/**
+	 * @ORM\OneToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity", mappedBy="manyToOne")
+	 * @var \Doctrine\Common\Collections\Collection&iterable<\PHPStan\Rules\Doctrine\ORM\AnotherEntity>
+	 */
+	private $oneToMany;
+
+	/**
+	 * @ORM\ManyToMany(targetEntity="PHPStan\Rules\Doctrine\ORM\AnotherEntity")
+	 * @var \Doctrine\Common\Collections\Collection&iterable<\PHPStan\Rules\Doctrine\ORM\AnotherEntity>
+	 */
+	private $manyToMany;
+
+}