IrIJIII) metallacycles were applied as catalysts for the hydrosilylation of various ketimines and aldimines with sodium tetrakisij(3,5-trifluoromethyl)phenyl]borate, NaBArF 24 , as an additive. By using a slight excess of the organosilane reagent, the reactions proceeded rapidly and efficiently, at low catalyst loadings and at room temperature. Several examples of cationic IrIJIII) catalysts could be synthesised, characterized and tested.In situ-generated catalysts proved to be more active as compared to isolated ones and species with non-coordinating BArF 24 counterion gave the highest catalytic activities.