In this study we describe a two-step synthesis method for the preparation of gold nanoparticles supported on tin modified silica. The key step of the preparation procedure is the formation of surface grafted organotin complexes. The reduction of these surface species in a hydrogen atmosphere resulted in both metallic (Sno) and ionic (Sn2+) forms of tin. These forms of tin are capable to reduce gold from chloroauric acid solution forming gold nanoparticles with high dispersion on the surface of silica. It has been found that the particle size of gold strongly depends on the pH value of the gold solution and the presence or absence of ammonia.