Herein we report an atom- and step-economic aromatic cyanoalkylation reaction that employs nitriles as building blocks and proceeds through C2-H and C3-H bond activation steps mediated by NiIII. In addition to cyanomethylation with MeCN, regioselective α-cyanoalkylation was observed with various nitrile substrates to generate secondary and tertiary nitriles. Importantly, to the best of our knowledge these are the first examples of C-H bond activation reactions occurring at a NiIII center, which may exhibit different reactivity and selectivity profiles than those corresponding to analogous NiII centers. These studies provide guiding principles to design catalytic C-H activation and functionalization reactions involving high-valent Ni species. © 2016 American Chemical Society.