diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
index b9cdc2b6920..aa0f913e862 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/contentassist2/CompletionTests.java
@@ -1734,4 +1734,12 @@ public class CompletionTests extends CompletionTestBase {
 		final String[] expected = { "B", "A", "waldo" };
 		assertCompletionResults(fCursorOffset, expected, ID);
 	}
+	
+	//	void waldo();
+	//	int main() {
+	//		wal/*cursor*/();
+	//	}
+	public void testExistingParens_72391() throws Exception {
+		assertCompletionResults(new String[] { "waldo" });  // expect no parens in replacement
+	}
 }
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/CContentAssistInvocationContext.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/CContentAssistInvocationContext.java
index 0ca11f5bb78..02590fa3572 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/CContentAssistInvocationContext.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/CContentAssistInvocationContext.java
@@ -195,6 +195,17 @@ public class CContentAssistInvocationContext extends ContentAssistInvocationCont
 			return token == Symbols.TokenSEMICOLON;
 		}
 	};
+	
+	private final Lazy<Boolean> followedByOpeningParen = new Lazy<Boolean>() {		
+		@Override
+		protected Boolean calculateValue() {
+			final IDocument doc = getDocument();
+			final int offset = getInvocationOffset();
+			final CHeuristicScanner.TokenStream tokenStream = new CHeuristicScanner.TokenStream(doc, offset);
+			final int token = tokenStream.nextToken();
+			return token == Symbols.TokenLPAREN;
+		}
+	};
 
 	private final Lazy<String> functionParameterDelimiter = new Lazy<String>() {
 		@Override
@@ -452,6 +463,11 @@ public class CContentAssistInvocationContext extends ContentAssistInvocationCont
 		assertNotDisposed();
 		return followedBySemicolon.value();
 	}
+	
+	public boolean isFollowedByOpeningParen() {		
+		assertNotDisposed();
+		return followedByOpeningParen.value();
+	}
 
 	public String getFunctionParameterDelimiter() {
 		assertNotDisposed();
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/DOMCompletionProposalComputer.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/DOMCompletionProposalComputer.java
index 04b9904f1dc..152814a9621 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/DOMCompletionProposalComputer.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/DOMCompletionProposalComputer.java
@@ -648,7 +648,7 @@ public class DOMCompletionProposalComputer extends ParsingBasedProposalComputer
 
         boolean inUsingDeclaration = cContext.isInUsingDirective();
 
-        if (canBeCall) {
+        if (canBeCall && !cContext.isFollowedByOpeningParen()) {
         	// If we might be calling the function in this context, assume we are
         	// (since that's the most common case) and emit parentheses.
         	repStringBuff.append('(');