The first phosphine-stabilized cationic rhodium silylene complex is reported. A dihydrido-silylene-Rh(iii) compound reacts with water and alcohols forming alkoxysilyl-Rh(iii) complexes and hydrogen gas. Moreover, benzophenone reacts with a cationic silylene rhodium complex leading to the reduction of the carbonyl group and the formation of an alkoxysilyl-Rh(iii) compound which has been identified as a likely intermediate in the mechanism for the hydrosilylation of ketones proposed by Hofmann and Gade.