The adsorption of nanometer-sized, palladium-phosphorus particles (Pd 0.86 Po 0.14 ) onto Si 3 N 4 , SiO 2 , and H-terminated Si(100) surfaces is described. These colloidal particles were prepared in aqueous solution by the reduction of Pd 2+ with hypophosphite in the presence of polyvinylpyrrolidone (PVP). The sterically stabilized particles catalyze Ni deposition from an electroless solution. High resolution electron microscopy shows that the particle size decreases with increasing PVP concentration in the sol. Several monocrystalline domains were observed in all particle samples. The surface affinity of Pd particles, covered with PVP, and of «free» PVP molecules (i.e., not associated with Pd particles) depends strongly on the type of surface. The large differences in Pd coverage between different types of surface (e.g., Si 3 N 4 and SiO 2 ) offer interesting possibilities for novel pattern-wise electroless metallization procedures