The geometries of the lowest-lying isomers of Au n Pt 2 , (n=1–4), clusters are determined using the density functional method B3LYP with relativistic effective core potentials (RECP) and LANL2DZ basis set. Several low-lying isomers were determined, and many of them in electronic configurations with a high spin multiplicity. The stability trend of Pt-doped Au n clusters are compared to that of pure Au n clusters. Our results show that the gold–platinum interaction is strong enough to improve the cluster stability, and indicate that the larger the Au n cluster is, smaller the distortions by substitution of the two Pt atoms are.