Abstract Catalytic properties of thermo-and photoactivated platinum complexes [Pt (R 2 R'X) 2 Cl 2](X= P, R= Me, R'= Ph; X= P, As, Sb, R= R'= Ph or Bu) in hydrosilylation of vinylsiloxanes with hydrosiloxanes were studied. The neutral ligands were ranked in terms of their effect on the activity of the catalysts. A mechanism of hydrosilylation was proposed.