Index: clang-tidy/readability/FunctionSizeCheck.h
===================================================================
--- clang-tidy/readability/FunctionSizeCheck.h
+++ clang-tidy/readability/FunctionSizeCheck.h
@@ -27,6 +27,8 @@
 ///     macro-heavy code. The default is `800`.
 ///   * `BranchThreshold` - flag functions exceeding this number of control
 ///     statements. The default is `-1` (ignore the number of branches).
+///   * `ParameterThreshold` - flag functions having a high number of parameters.
+///     The default is `6`.
 class FunctionSizeCheck : public ClangTidyCheck {
 public:
   FunctionSizeCheck(StringRef Name, ClangTidyContext *Context);
@@ -39,6 +41,7 @@
   const unsigned LineThreshold;
   const unsigned StatementThreshold;
   const unsigned BranchThreshold;
+  const unsigned ParameterThreshold;
 };
 
 } // namespace readability
Index: clang-tidy/readability/FunctionSizeCheck.cpp
===================================================================
--- clang-tidy/readability/FunctionSizeCheck.cpp
+++ clang-tidy/readability/FunctionSizeCheck.cpp
@@ -72,12 +72,14 @@
     : ClangTidyCheck(Name, Context),
       LineThreshold(Options.get("LineThreshold", -1U)),
       StatementThreshold(Options.get("StatementThreshold", 800U)),
-      BranchThreshold(Options.get("BranchThreshold", -1U)) {}
+      BranchThreshold(Options.get("BranchThreshold", -1U)),
+      ParameterThreshold(Options.get("ParameterThreshold", 6)) {}
 
 void FunctionSizeCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "LineThreshold", LineThreshold);
   Options.store(Opts, "StatementThreshold", StatementThreshold);
   Options.store(Opts, "BranchThreshold", BranchThreshold);
+  Options.store(Opts, "ParameterThreshold", ParameterThreshold);
 }
 
 void FunctionSizeCheck::registerMatchers(MatchFinder *Finder) {
@@ -103,8 +105,11 @@
     }
   }
 
+  unsigned ActualNumberParameters = Func->getNumParams();
+
   if (FI.Lines > LineThreshold || FI.Statements > StatementThreshold ||
-      FI.Branches > BranchThreshold) {
+      FI.Branches > BranchThreshold ||
+      ActualNumberParameters > ParameterThreshold) {
     diag(Func->getLocation(),
          "function %0 exceeds recommended size/complexity thresholds")
         << Func;
@@ -127,6 +132,12 @@
     diag(Func->getLocation(), "%0 branches (threshold %1)", DiagnosticIDs::Note)
         << FI.Branches << BranchThreshold;
   }
+
+  if (ActualNumberParameters > ParameterThreshold) {
+    diag(Func->getLocation(), "%0 parameters (threshold %1)",
+         DiagnosticIDs::Note)
+        << ActualNumberParameters << ParameterThreshold;
+  }
 }
 
 } // namespace readability
Index: test/clang-tidy/readability-function-size.cpp
===================================================================
--- test/clang-tidy/readability-function-size.cpp
+++ test/clang-tidy/readability-function-size.cpp
@@ -1,54 +1,79 @@
-// RUN: %check_clang_tidy %s readability-function-size %t -- -config='{CheckOptions: [{key: readability-function-size.LineThreshold, value: 0}, {key: readability-function-size.StatementThreshold, value: 0}, {key: readability-function-size.BranchThreshold, value: 0}]}' -- -std=c++11
+// RUN: %check_clang_tidy %s readability-function-size %t -- -config='{CheckOptions: [{key: readability-function-size.LineThreshold, value: 0}, {key: readability-function-size.StatementThreshold, value: 0}, {key: readability-function-size.BranchThreshold, value: 0}, {key: readability-function-size.ParameterThreshold, value: 5}]}' -- -std=c++11
 
 void foo1() {
 }
 
-void foo2() {;}
+void foo2() { ; }
 // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'foo2' exceeds recommended size/complexity thresholds [readability-function-size]
 // CHECK-MESSAGES: :[[@LINE-2]]:6: note: 1 statements (threshold 0)
 
 void foo3() {
-;
-
+  ;
 }
-// CHECK-MESSAGES: :[[@LINE-4]]:6: warning: function 'foo3' exceeds recommended size/complexity
-// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 3 lines including whitespace and comments (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-6]]:6: note: 1 statements (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-3]]:6: warning: function 'foo3' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-4]]:6: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 1 statements (threshold 0)
 
-void foo4(int i) { if (i) {} else; {}
+void foo4(int i) {
+  if (i) {
+  } else
+    ;
+  {}
 }
-// CHECK-MESSAGES: :[[@LINE-2]]:6: warning: function 'foo4' exceeds recommended size/complexity
-// CHECK-MESSAGES: :[[@LINE-3]]:6: note: 1 lines including whitespace and comments (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-4]]:6: note: 3 statements (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 1 branches (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-6]]:6: warning: function 'foo4' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-7]]:6: note: 5 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-8]]:6: note: 3 statements (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-9]]:6: note: 1 branches (threshold 0)
 
-void foo5(int i) {for(;i;)while(i)
-do;while(i);
+void foo5(int i) {
+  for (; i;)
+    while (i)
+      do
+        ;
+      while (i);
 }
-// CHECK-MESSAGES: :[[@LINE-3]]:6: warning: function 'foo5' exceeds recommended size/complexity
-// CHECK-MESSAGES: :[[@LINE-4]]:6: note: 2 lines including whitespace and comments (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 7 statements (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-6]]:6: note: 3 branches (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-7]]:6: warning: function 'foo5' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-8]]:6: note: 6 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-9]]:6: note: 7 statements (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-10]]:6: note: 3 branches (threshold 0)
 
-template <typename T> T foo6(T i) {return i;
+template <typename T>
+T foo6(T i) {
+  return i;
 }
 int x = foo6(0);
-// CHECK-MESSAGES: :[[@LINE-3]]:25: warning: function 'foo6' exceeds recommended size/complexity
-// CHECK-MESSAGES: :[[@LINE-4]]:25: note: 1 lines including whitespace and comments (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-5]]:25: note: 1 statements (threshold 0)
-
-void bar1() { [](){;;;;;;;;;;;if(1){}}();
+// CHECK-MESSAGES: :[[@LINE-4]]:3: warning: function 'foo6' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-5]]:3: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-6]]:3: note: 1 statements (threshold 0)
 
+void foo7(int p1, int p2, int p3, int p4, int p5, int p6, int p7) {
+  ;
+}
+// CHECK-MESSAGES: :[[@LINE-3]]:6: warning: function 'foo7' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-4]]:6: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 1 statements (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-6]]:6: note: 7 parameters (threshold 5)
 
+void bar1() {
+  []() {;;;;;;;;;;;if(1){} }();
 }
-// CHECK-MESSAGES: :[[@LINE-4]]:6: warning: function 'bar1' exceeds recommended size/complexity
-// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 3 lines including whitespace and comments (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-6]]:6: note: 14 statements (threshold 0)
-// CHECK-MESSAGES: :[[@LINE-7]]:6: note: 1 branches (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-3]]:6: warning: function 'bar1' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-4]]:6: note: 2 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-5]]:6: note: 14 statements (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-6]]:6: note: 1 branches (threshold 0)
 
-void bar2() { class A { void barx() {;;} }; }
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'bar2' exceeds recommended size/complexity
-// CHECK-MESSAGES: :[[@LINE-2]]:6: note: 3 statements (threshold 0)
+void bar2() {
+  class A {
+    void barx() {
+      ;
+      ;
+    }
+  };
+}
+// CHECK-MESSAGES: :[[@LINE-8]]:6: warning: function 'bar2' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-9]]:6: note: 7 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-10]]:6: note: 3 statements (threshold 0)
 //
-// CHECK-MESSAGES: :[[@LINE-4]]:30: warning: function 'barx' exceeds recommended size/complexity
-// CHECK-MESSAGES: :[[@LINE-5]]:30: note: 2 statements (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-10]]:10: warning: function 'barx' exceeds recommended size/complexity thresholds [readability-function-size]
+// CHECK-MESSAGES: :[[@LINE-11]]:10: note: 3 lines including whitespace and comments (threshold 0)
+// CHECK-MESSAGES: :[[@LINE-12]]:10: note: 2 statements (threshold 0)