The copper-catalyzed cyanation of aryl iodides is described using nitromethane as a CN source. In situ generation of a "CN" species from nitromethane is plausible. This strategy is an advantageous synthetic method for the construction of an aromatic C-CN bond, because nitromethane is a common and easily handled compound that is readily available as a cyanation reagent, and its use allows the avoidance of using toxic metal cyanides.