Chiral aryl diphosphite ligands derived from binaphthol were found to be effective in the nickel-catalyzed hydrocyanation of a variety of olefins. Enantioselective hydrocyanations of styrene, 4-substituted styrenes and norbornene were achieved with excellent regioselectivity and moderate enantioselectivity. The hydrocyanation of vinyl acetate gave 72.9% ee. The catalytic activity and the enantioselectivity of the Ni(0)-diphosphite complexes were found to be highly dependent on the structures of the ligands.