In this short note we prove that there is a constant c such that every k-edge-coloring of the complete graph Kn with n 2ck contains a K4 whose edges receive at most two colors. This improves on a result of Kostochka and Mubayi, and is the first exponential bound for this problem. Key words. Ramsey-type problems, dependent random choice, probabilistic method AMS subject classifications. 05C55, 05C35, 05D10, 05D40 DOI. 10.1137/070706628