diff --git a/openapi_core/schema/schemas/models.py b/openapi_core/schema/schemas/models.py
index b783cae..44fa022 100644
--- a/openapi_core/schema/schemas/models.py
+++ b/openapi_core/schema/schemas/models.py
@@ -6,12 +6,12 @@ import warnings
 from six import iteritems
 
 from openapi_core.extensions.models.factories import ModelFactory
-from openapi_core.schema.schemas.enums import SchemaType
+from openapi_core.schema.schemas.enums import SchemaFormat, SchemaType
 from openapi_core.schema.schemas.exceptions import (
     InvalidSchemaValue, UndefinedSchemaProperty, MissingSchemaProperty,
     OpenAPISchemaError, NoOneOfSchema, MultipleOneOfSchema,
 )
-from openapi_core.schema.schemas.util import forcebool
+from openapi_core.schema.schemas.util import forcebool, format_date
 
 log = logging.getLogger(__name__)
 
@@ -25,6 +25,10 @@ class Schema(object):
         SchemaType.BOOLEAN: forcebool,
     }
 
+    FORMAT_CALLABLE_GETTER = defaultdict(lambda: lambda x: x, {
+        SchemaFormat.DATE.value: format_date,
+    })
+
     def __init__(
             self, schema_type=None, model=None, properties=None, items=None,
             schema_format=None, required=None, default=None, nullable=False,
@@ -92,6 +96,7 @@ class Schema(object):
     def get_cast_mapping(self):
         mapping = self.DEFAULT_CAST_CALLABLE_GETTER.copy()
         mapping.update({
+            SchemaType.STRING: self._unmarshal_string,
             SchemaType.ARRAY: self._unmarshal_collection,
             SchemaType.OBJECT: self._unmarshal_object,
         })
@@ -110,7 +115,7 @@ class Schema(object):
 
         cast_mapping = self.get_cast_mapping()
 
-        if self.type in cast_mapping and value == '':
+        if self.type is not SchemaType.STRING and value == '':
             return None
 
         cast_callable = cast_mapping[self.type]
@@ -139,6 +144,16 @@ class Schema(object):
 
         return casted
 
+    def _unmarshal_string(self, value):
+        formatter = self.FORMAT_CALLABLE_GETTER[self.format]
+        try:
+            return formatter(value)
+        except ValueError:
+            raise InvalidSchemaValue(
+                "Failed to format value of {0} to {1}".format(
+                    value, self.format)
+            )
+
     def _unmarshal_collection(self, value):
         return list(map(self.items.unmarshal, value))
 
diff --git a/openapi_core/schema/schemas/util.py b/openapi_core/schema/schemas/util.py
index 337b925..3291276 100644
--- a/openapi_core/schema/schemas/util.py
+++ b/openapi_core/schema/schemas/util.py
@@ -1,4 +1,5 @@
 """OpenAPI core schemas util module"""
+import datetime
 from distutils.util import strtobool
 from json import dumps
 from six import string_types
@@ -13,3 +14,7 @@ def forcebool(val):
 
 def dicthash(d):
     return hash(dumps(d, sort_keys=True))
+
+
+def format_date(value):
+    return datetime.datetime.strptime(value, '%Y-%m-%d').date()
diff --git a/tests/unit/schema/test_schemas.py b/tests/unit/schema/test_schemas.py
index 423b098..ed4f8fe 100644
--- a/tests/unit/schema/test_schemas.py
+++ b/tests/unit/schema/test_schemas.py
@@ -1,3 +1,5 @@
+import datetime
+
 import mock
 import pytest
 
@@ -64,6 +66,49 @@ class TestSchemaUnmarshal(object):
 
         assert result == default_value
 
+    def test_string_format_date(self):
+        schema = Schema('string', schema_format='date')
+        value = '2018-01-02'
+
+        result = schema.unmarshal(value)
+
+        assert result == datetime.date(2018, 1, 2)
+
+    def test_string_format_custom(self):
+        custom_format = 'custom'
+        schema = Schema('string', schema_format=custom_format)
+        value = 'x'
+
+        with mock.patch.dict(
+            Schema.FORMAT_CALLABLE_GETTER,
+            {custom_format: lambda x: x + '-custom'},
+        ):
+            result = schema.unmarshal(value)
+
+        assert result == 'x-custom'
+
+    def test_string_format_unknown(self):
+        unknown_format = 'unknown'
+        schema = Schema('string', schema_format=unknown_format)
+        value = 'x'
+
+        result = schema.unmarshal(value)
+
+        assert result == 'x'
+
+    def test_string_format_invalid_value(self):
+        custom_format = 'custom'
+        schema = Schema('string', schema_format=custom_format)
+        value = 'x'
+
+        with mock.patch.dict(
+            Schema.FORMAT_CALLABLE_GETTER,
+            {custom_format: mock.Mock(side_effect=ValueError())},
+        ), pytest.raises(
+            InvalidSchemaValue, message='Failed to format value'
+        ):
+            schema.unmarshal(value)
+
     def test_integer_valid(self):
         schema = Schema('integer')
         value = '123'