gamma -Al2O3-supported Pd, Pt, and bimetallic Pd-Pt catalysts have been produced by laser vaporization of the respective bulk metals and alloys. Transmission electron microscopy and energy-dispersive X-ray analysis experiments show that these bimetallic clusters have a perfectly well defined stoichioemetry. Moreover, pure or bimetallic clusters have similar size distributions. One has taken benefit of these features to study in detail the resistance to sulfur poisoning as a function of the composition and to verify to what extent what is claimed in the literature, i.e., an improved resistance to sulfur poisoning of Pd-Pt catalysts as compared to pure metals, is verified. The catalytic properties of Pd, Pt, Pd17Pt83, and Pd65Pt35 in the hydrogenation of tetralin in the presence of varied amounts of H2S have been compared. Contrary to what is claimed, the coexistence of Pd with Pt in the same particle has no influence on the hydrogenation activity nor on the sulfur tolerance of the catalysts. Hence, it has been shown that Pt has no electronic influence on the reactivity of Pd atoms.