A dinitrile is hydrogenated to an omega-aminonitrile with hydrogen in an aprotic solvent with a supported rhodium catalyst and ammonia present. The catalyst is prepared by hydrolyzing a rhodium(III) halide with strong aqueous base at elevated temperatures, drying the supported rhodium hydroxide at elevated temperatures and hydrogenating the dried product at elevated temperatures. High conversions, selectivity to aminonitrile and catalyst recyclability are achieved.