A highly efficient copper-catalyzed cyclization/cyanation cascade of unactivated olefins bearing oximes is described. A variety of cyano-containing isoxazolines have been obtained in high yields with cheap Cu(NO3)2·3H2O as the catalyst and TMSCN as the non-metallic cyanide source. The present method provides a mild, simple, and practical access to cyano-substituted isoxazolines and is amenable to gram scale. The simultaneous construction of C(sp3)-CN and C-O bonds can be achieved in one step.