diff --git a/src/services/services.ts b/src/services/services.ts
index 1618fb6e276..a88b31bd2fe 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -335,36 +335,43 @@ module ts {
             var paramTag = "@param";
             var jsDocCommentParts: SymbolDisplayPart[] = [];
 
-            ts.forEach(declarations, declaration => {
-                var sourceFileOfDeclaration = getSourceFileOfNode(declaration);
-                // If it is parameter - try and get the jsDoc comment with @param tag from function declaration's jsDoc comments
-                if (canUseParsedParamTagComments && declaration.kind === SyntaxKind.Parameter) {
-                    ts.forEach(getJsDocCommentTextRange(declaration.parent, sourceFileOfDeclaration), jsDocCommentTextRange => {
-                        var cleanedParamJsDocComment = getCleanedParamJsDocComment(jsDocCommentTextRange.pos, jsDocCommentTextRange.end, sourceFileOfDeclaration);
-                        if (cleanedParamJsDocComment) {
-                            jsDocCommentParts.push.apply(jsDocCommentParts, cleanedParamJsDocComment);
-                        }
-                    });
+            ts.forEach(declarations,(declaration, indexOfDeclaration) => {
+                if (indexOf(declarations, declaration) === indexOfDeclaration) {
+                    // Already collected the doc comments from this declaration.
+                    // Eg. var a: Array<string> | Array<number>; a.length
+                    // The property length will have two declarations of property length coming 
+                    // from Array<T> - Array<string> and Array<number>
+                
+                    var sourceFileOfDeclaration = getSourceFileOfNode(declaration);
+                    // If it is parameter - try and get the jsDoc comment with @param tag from function declaration's jsDoc comments
+                    if (canUseParsedParamTagComments && declaration.kind === SyntaxKind.Parameter) {
+                        ts.forEach(getJsDocCommentTextRange(declaration.parent, sourceFileOfDeclaration), jsDocCommentTextRange => {
+                            var cleanedParamJsDocComment = getCleanedParamJsDocComment(jsDocCommentTextRange.pos, jsDocCommentTextRange.end, sourceFileOfDeclaration);
+                            if (cleanedParamJsDocComment) {
+                                jsDocCommentParts.push.apply(jsDocCommentParts, cleanedParamJsDocComment);
+                            }
+                        });
+                    }
+
+                    // If this is left side of dotted module declaration, there is no doc comments associated with this node
+                    if (declaration.kind === SyntaxKind.ModuleDeclaration && (<ModuleDeclaration>declaration).body.kind === SyntaxKind.ModuleDeclaration) {
+                        return;
+                    }
+
+                    // If this is dotted module name, get the doc comments from the parent
+                    while (declaration.kind === SyntaxKind.ModuleDeclaration && declaration.parent.kind === SyntaxKind.ModuleDeclaration) {
+                        declaration = <ModuleDeclaration>declaration.parent;
+                    } 
+
+                    // Get the cleaned js doc comment text from the declaration
+                    ts.forEach(getJsDocCommentTextRange(
+                        declaration.kind === SyntaxKind.VariableDeclaration ? declaration.parent.parent : declaration, sourceFileOfDeclaration), jsDocCommentTextRange => {
+                            var cleanedJsDocComment = getCleanedJsDocComment(jsDocCommentTextRange.pos, jsDocCommentTextRange.end, sourceFileOfDeclaration);
+                            if (cleanedJsDocComment) {
+                                jsDocCommentParts.push.apply(jsDocCommentParts, cleanedJsDocComment);
+                            }
+                        });
                 }
-
-                // If this is left side of dotted module declaration, there is no doc comments associated with this node
-                if (declaration.kind === SyntaxKind.ModuleDeclaration && (<ModuleDeclaration>declaration).body.kind === SyntaxKind.ModuleDeclaration) {
-                    return;
-                }
-
-                // If this is dotted module name, get the doc comments from the parent
-                while (declaration.kind === SyntaxKind.ModuleDeclaration && declaration.parent.kind === SyntaxKind.ModuleDeclaration) {
-                    declaration = <ModuleDeclaration>declaration.parent;
-                } 
-
-                // Get the cleaned js doc comment text from the declaration
-                ts.forEach(getJsDocCommentTextRange(
-                    declaration.kind === SyntaxKind.VariableDeclaration ? declaration.parent.parent : declaration, sourceFileOfDeclaration), jsDocCommentTextRange => {
-                        var cleanedJsDocComment = getCleanedJsDocComment(jsDocCommentTextRange.pos, jsDocCommentTextRange.end, sourceFileOfDeclaration);
-                        if (cleanedJsDocComment) {
-                            jsDocCommentParts.push.apply(jsDocCommentParts, cleanedJsDocComment);
-                        }
-                    });
             });
 
             return jsDocCommentParts;
diff --git a/tests/cases/fourslash/commentsUnion.ts b/tests/cases/fourslash/commentsUnion.ts
new file mode 100644
index 00000000000..568e0d93cde
--- /dev/null
+++ b/tests/cases/fourslash/commentsUnion.ts
@@ -0,0 +1,7 @@
+/// <reference path='fourslash.ts' />
+
+////var a: Array<string> | Array<number>;
+////a./*1*/length
+
+goTo.marker('1');
+verify.quickInfoIs("(property) length: number", "Gets or sets the length of the array. This is a number one higher than the highest element defined in an array.");
\ No newline at end of file