diff --git a/openapi_core/validation/request/validators.py b/openapi_core/validation/request/validators.py
index c36b6a20..734b5894 100644
--- a/openapi_core/validation/request/validators.py
+++ b/openapi_core/validation/request/validators.py
@@ -1,4 +1,5 @@
 """OpenAPI core validation request validators module"""
+from itertools import chain
 from six import iteritems
 
 from openapi_core.schema.exceptions import OpenAPIMappingError
@@ -28,30 +29,34 @@ def validate(self, request):
 
         try:
             path = self.spec[operation_pattern]
-        # don't process if operation errors
-        except OpenAPIMappingError as exc:
-            return RequestValidationResult([exc, ], None, None)
-
-        path_params, path_params_errors = self._get_parameters(request, path)
-
-        try:
             operation = self.spec.get_operation(
                 operation_pattern, request.method)
         # don't process if operation errors
         except OpenAPIMappingError as exc:
             return RequestValidationResult([exc, ], None, None)
 
-        op_params, op_params_errors = self._get_parameters(request, operation)
+        params, params_errors = self._get_parameters(
+            request, chain(
+                iteritems(operation.parameters),
+                iteritems(path.parameters)
+            )
+        )
+
         body, body_errors = self._get_body(request, operation)
 
-        errors = path_params_errors + op_params_errors + body_errors
-        return RequestValidationResult(errors, body, path_params + op_params)
+        errors = params_errors + body_errors
+        return RequestValidationResult(errors, body, params)
 
-    def _get_parameters(self, request, operation):
+    def _get_parameters(self, request, params):
         errors = []
-
+        seen = set()
         parameters = RequestParameters()
-        for param_name, param in iteritems(operation.parameters):
+        for param_name, param in params:
+            if (param_name, param.location.value) in seen:
+                # skip parameter already seen
+                # e.g. overriden path item paremeter on operation
+                continue
+            seen.add((param_name, param.location.value))
             try:
                 raw_value = param.get_value(request)
             except MissingParameter:
diff --git a/tests/integration/test_validators.py b/tests/integration/test_validators.py
index d6e6a5a3..2f26a7bc 100644
--- a/tests/integration/test_validators.py
+++ b/tests/integration/test_validators.py
@@ -235,7 +235,7 @@ def test_get_pet(self, validator):
 class TestPathItemParamsValidator(object):
 
     @pytest.fixture
-    def spec_dict(self, factory):
+    def spec_dict(self):
         return {
             "openapi": "3.0.0",
             "info": {
@@ -305,6 +305,50 @@ def test_request_valid_param(self, validator):
         assert result.body is None
         assert result.parameters == {'query': {'resId': 10}}
 
+    def test_request_override_param(self, spec_dict):
+        # override path parameter on operation
+        spec_dict["paths"]["/resource"]["get"]["parameters"] = [
+            {
+                # full valid parameter object required
+                "name": "resId",
+                "in": "query",
+                "required": False,
+                "schema": {
+                    "type": "integer",
+                },
+            }
+        ]
+        validator = RequestValidator(create_spec(spec_dict))
+        request = MockRequest('http://example.com', 'get', '/resource')
+        result = validator.validate(request)
+
+        assert len(result.errors) == 0
+        assert result.body is None
+        assert result.parameters == {}
+
+    def test_request_override_param_uniqueness(self, spec_dict):
+        # add parameter on operation with same name as on path but
+        # different location
+        spec_dict["paths"]["/resource"]["get"]["parameters"] = [
+            {
+                # full valid parameter object required
+                "name": "resId",
+                "in": "header",
+                "required": False,
+                "schema": {
+                    "type": "integer",
+                },
+            }
+        ]
+        validator = RequestValidator(create_spec(spec_dict))
+        request = MockRequest('http://example.com', 'get', '/resource')
+        result = validator.validate(request)
+
+        assert len(result.errors) == 1
+        assert type(result.errors[0]) == MissingRequiredParameter
+        assert result.body is None
+        assert result.parameters == {}
+
 
 class TestResponseValidator(object):