diff --git a/moto/rds2/models.py b/moto/rds2/models.py
index 354d7fd70..eda181f40 100644
--- a/moto/rds2/models.py
+++ b/moto/rds2/models.py
@@ -58,6 +58,8 @@ class Database(BaseModel):
         self.source_db_identifier = kwargs.get("source_db_identifier")
         self.db_instance_class = kwargs.get('db_instance_class')
         self.port = kwargs.get('port')
+        if self.port is None:
+            self.port = Database.default_port(self.engine)
         self.db_instance_identifier = kwargs.get('db_instance_identifier')
         self.db_name = kwargs.get("db_name")
         self.publicly_accessible = kwargs.get("publicly_accessible")
@@ -242,6 +244,22 @@ class Database(BaseModel):
             return self.port
         raise UnformattedGetAttTemplateException()
 
+    @staticmethod
+    def default_port(engine):
+        return {
+            'mysql': 3306,
+            'mariadb': 3306,
+            'postgres': 5432,
+            'oracle-ee': 1521,
+            'oracle-se2': 1521,
+            'oracle-se1': 1521,
+            'oracle-se': 1521,
+            'sqlserver-ee': 1433,
+            'sqlserver-ex': 1433,
+            'sqlserver-se': 1433,
+            'sqlserver-web': 1433,
+        }[engine]
+
     @classmethod
     def create_from_cloudformation_json(cls, resource_name, cloudformation_json, region_name):
         properties = cloudformation_json['Properties']
diff --git a/tests/test_rds2/test_rds2.py b/tests/test_rds2/test_rds2.py
index 915695ad8..7eadf2d36 100644
--- a/tests/test_rds2/test_rds2.py
+++ b/tests/test_rds2/test_rds2.py
@@ -992,6 +992,20 @@ def test_create_db_instance_with_parameter_group():
         'ParameterApplyStatus'].should.equal('in-sync')
 
 
+@disable_on_py3()
+@mock_rds2
+def test_create_database_with_default_port():
+    conn = boto3.client('rds', region_name='us-west-2')
+    database = conn.create_db_instance(DBInstanceIdentifier='db-master-1',
+                                       AllocatedStorage=10,
+                                       Engine='postgres',
+                                       DBInstanceClass='db.m1.small',
+                                       MasterUsername='root',
+                                       MasterUserPassword='hunter2',
+                                       DBSecurityGroups=["my_sg"])
+    database['DBInstance']['Endpoint']['Port'].should.equal(5432)
+
+
 @disable_on_py3()
 @mock_rds2
 def test_modify_db_instance_with_parameter_group():