Abstract: The invention concerns the hydrogenation in amine function of a nitrile function of a dinitrile to obtain the corresponding aminonitrile. More precisely, the invention concerns the hemihydrogenation of a dinitrile into the corresponding aminonitrile, in a liquid medium, characterized in that it consists in operating in the presence of a Raney nickel or cobalt catalyst containing copper and/or silver and/or gold and in the presence of an alkaline or alkaline-earth metal hydroxide. The hemihydrogenation of adiponitrile provides amino-6 capronitrile, compound which can be easily transformed by cyclization hydrolysis into caprolactam, the starting product for the synthesis of polyamide-6.