Triangular gold nanoplates were prepared by the tartaric acid reduction of HAuCl4 in cationic surfactant solutions, in the absence and the presence of small amounts of AgNO3 and CuSO4. With increasing concentration of AgNO3, the particle shape changes from triangular to spherical. In the presence of CuSO4, triangular plates with side lengths and tips that are longer and sharper, respectively, than those of the nanoplates prepared in the absence of CuSO4, are obtained.