An iron-catalyzed radical cascade cyclization of oxime esters with isocyanides for the synthesis of 1-cyanoalkyl isoquinolines and 6-cyanoalkyl phenanthridines has been developed. This demonstrates excellent functional group tolerance and broad substrate scope. A diverse range of potentially valuable 1-cyanoalkyl isoquinolines and 6-cyanoalkyl phenanthridines were obtained in moderate to good yields.