diff --git a/gtsam.h b/gtsam.h
index 0fd782309..14e3d175f 100644
--- a/gtsam.h
+++ b/gtsam.h
@@ -919,6 +919,7 @@ virtual class JacobianFactor : gtsam::GaussianFactor {
 			Vector b, const gtsam::noiseModel::Diagonal* model);
 	JacobianFactor(const gtsam::GaussianFactor& factor);
 	void print(string s) const;
+	void printKeys(string s) const;
 	bool equals(const gtsam::GaussianFactor& lf, double tol) const;
 	bool empty() const;
 	size_t size() const;
@@ -942,6 +943,7 @@ virtual class HessianFactor : gtsam::GaussianFactor {
 	HessianFactor(const gtsam::GaussianFactor& factor);
 	size_t size() const;
 	void print(string s) const;
+	void printKeys(string s) const;
 	bool equals(const gtsam::GaussianFactor& lf, double tol) const;
 	double error(const gtsam::VectorValues& c) const;
 	gtsam::GaussianFactor* negate() const;
@@ -1088,6 +1090,7 @@ class NonlinearFactorGraph {
 
 virtual class NonlinearFactor {
 	void print(string s) const;
+	void printKeys(string s) const;
 	void equals(const gtsam::NonlinearFactor& other, double tol) const;
 	gtsam::KeyVector keys() const;
 	size_t size() const;
diff --git a/gtsam/inference/Factor-inl.h b/gtsam/inference/Factor-inl.h
index 6636b646c..b2099aa3e 100644
--- a/gtsam/inference/Factor-inl.h
+++ b/gtsam/inference/Factor-inl.h
@@ -58,10 +58,16 @@ namespace gtsam {
 	template<typename KEY>
 	void Factor<KEY>::print(const std::string& s,
 			const IndexFormatter& formatter) const {
+		printKeys(s,formatter);
+	}
+
+	/* ************************************************************************* */
+	template<typename KEY>
+  void Factor<KEY>::printKeys(const std::string& s, const IndexFormatter& formatter) const {
 		std::cout << s << " ";
 		BOOST_FOREACH(KEY key, keys_) std::cout << " " << formatter(key);
 		std::cout << std::endl;
-	}
+  }
 
 	/* ************************************************************************* */
 	template<typename KEY>
diff --git a/gtsam/inference/Factor.h b/gtsam/inference/Factor.h
index 950f6e65f..4c31664d7 100644
--- a/gtsam/inference/Factor.h
+++ b/gtsam/inference/Factor.h
@@ -187,6 +187,10 @@ public:
   void print(const std::string& s = "Factor",
   		const IndexFormatter& formatter = DefaultIndexFormatter) const;
 
+  /// print only keys
+  void printKeys(const std::string& s = "Factor",
+  		const IndexFormatter& formatter = DefaultIndexFormatter) const;
+
   /// check equality
   bool equals(const This& other, double tol = 1e-9) const;