Index: clang-tidy/google/CMakeLists.txt
===================================================================
--- clang-tidy/google/CMakeLists.txt
+++ clang-tidy/google/CMakeLists.txt
@@ -2,6 +2,7 @@
 
 add_clang_library(clangTidyGoogleModule
   AvoidCStyleCastsCheck.cpp
+  DefaultArgumentsCheck.cpp
   ExplicitConstructorCheck.cpp
   ExplicitMakePairCheck.cpp
   GlobalNamesInHeadersCheck.cpp
Index: clang-tidy/google/DefaultArgumentsCheck.h
===================================================================
--- /dev/null
+++ clang-tidy/google/DefaultArgumentsCheck.h
@@ -0,0 +1,34 @@
+//===--- DefaultArgumentsCheck.h - clang-tidy--------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_DEFAULT_ARGUMENTS_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_DEFAULT_ARGUMENTS_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace google {
+
+/// Checks that default parameters are not given for virtual methods.
+///
+/// See https://google.github.io/styleguide/cppguide.html#Default_Arguments
+class DefaultArgumentsCheck : public ClangTidyCheck {
+public:
+  DefaultArgumentsCheck(StringRef Name, ClangTidyContext *Context)
+      : ClangTidyCheck(Name, Context) {}
+  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+};
+
+} // namespace google
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_GOOGLE_DEFAULT_ARGUMENTS_H
Index: clang-tidy/google/DefaultArgumentsCheck.cpp
===================================================================
--- /dev/null
+++ clang-tidy/google/DefaultArgumentsCheck.cpp
@@ -0,0 +1,36 @@
+//===--- DefaultArgumentsCheck.cpp - clang-tidy----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "DefaultArgumentsCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace google {
+
+void DefaultArgumentsCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(
+      cxxMethodDecl(anyOf(isOverride(), isVirtual()),
+                    hasAnyParameter(parmVarDecl(hasInitializer(expr()))))
+          .bind("Decl"),
+      this);
+}
+
+void DefaultArgumentsCheck::check(const MatchFinder::MatchResult &Result) {
+  const auto *MatchedDecl = Result.Nodes.getNodeAs<CXXMethodDecl>("Decl");
+  diag(MatchedDecl->getLocation(),
+       "default argument given for virtual or override method.");
+}
+
+} // namespace google
+} // namespace tidy
+} // namespace clang
Index: clang-tidy/google/GoogleTidyModule.cpp
===================================================================
--- clang-tidy/google/GoogleTidyModule.cpp
+++ clang-tidy/google/GoogleTidyModule.cpp
@@ -15,6 +15,7 @@
 #include "../readability/NamespaceCommentCheck.h"
 #include "../readability/RedundantSmartptrGetCheck.h"
 #include "AvoidCStyleCastsCheck.h"
+#include "DefaultArgumentsCheck.h"
 #include "ExplicitConstructorCheck.h"
 #include "ExplicitMakePairCheck.h"
 #include "GlobalNamesInHeadersCheck.h"
@@ -36,6 +37,8 @@
 class GoogleModule : public ClangTidyModule {
 public:
   void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+    CheckFactories.registerCheck<DefaultArgumentsCheck>(
+        "google-default-arguments");
     CheckFactories.registerCheck<build::ExplicitMakePairCheck>(
         "google-build-explicit-make-pair");
     CheckFactories.registerCheck<build::UnnamedNamespaceInHeaderCheck>(
Index: docs/ReleaseNotes.rst
===================================================================
--- docs/ReleaseNotes.rst
+++ docs/ReleaseNotes.rst
@@ -86,6 +86,11 @@
   Flags user-defined constructor definitions that do not initialize all builtin
   and pointer fields which leaves their memory in an undefined state.
 
+- New `google-default-arguments
+  <http://clang.llvm.org/extra/clang-tidy/checks/google-default-arguments.html>`_ check
+
+  Flags default arguments in vitual methods.
+
 - New `misc-dangling-handle
   <http://clang.llvm.org/extra/clang-tidy/checks/misc-dangling-handle.html>`_ check
 
Index: docs/clang-tidy/checks/google-default-arguments.rst
===================================================================
--- /dev/null
+++ docs/clang-tidy/checks/google-default-arguments.rst
@@ -0,0 +1,8 @@
+.. title:: clang-tidy - google-default-arguments
+
+google-default-arguments
+========================
+
+Checks that default parameters are not given for virtual methods.
+
+See https://google.github.io/styleguide/cppguide.html#Default_Arguments
Index: docs/clang-tidy/checks/list.rst
===================================================================
--- docs/clang-tidy/checks/list.rst
+++ docs/clang-tidy/checks/list.rst
@@ -30,6 +30,7 @@
    google-build-explicit-make-pair
    google-build-namespaces
    google-build-using-namespace
+   google-default-arguments
    google-explicit-constructor
    google-global-names-in-headers
    google-readability-braces-around-statements (redirects to readability-braces-around-statements) <google-readability-braces-around-statements>
@@ -75,7 +76,7 @@
    misc-string-literal-with-embedded-nul
    misc-suspicious-missing-comma
    misc-suspicious-semicolon
-   misc-suspicious-string-compare   
+   misc-suspicious-string-compare
    misc-swapped-arguments
    misc-throw-by-value-catch-by-reference
    misc-undelegated-constructor
Index: test/clang-tidy/google-default-arguments.cpp
===================================================================
--- /dev/null
+++ test/clang-tidy/google-default-arguments.cpp
@@ -0,0 +1,29 @@
+// RUN: %check_clang_tidy %s google-default-arguments %t
+
+struct A {
+  virtual void f(int I, int J = 3);
+  // CHECK-MESSAGES: :[[@LINE-1]]:16: warning: default argument given for virtual or override method
+};
+
+struct B : public A {
+  void f(int I, int J = 5);
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: default argument given for virtual or override method
+};
+
+struct C : public B {
+  void f(int I, int J = 5) override;
+  // CHECK-MESSAGES: :[[@LINE-1]]:8: warning: default argument given for virtual or override method
+};
+
+// Negatives.
+struct D : public B {
+  void f(int I, int J) override;
+};
+
+struct X {
+  void f(int I, int J = 3);
+};
+
+struct Y : public X {
+  void f(int I, int J = 5);
+};