The greener synthesis of N-substituted isonicotinamides is of high importance and remains a significant challenge to the chemistry community. Herein we delineated a visible-light-driven, transition-metal-free, external-oxidant-free radical-radical cross-coupling reaction to access the N-substituted isonicotinamides via consecutive photoinduced electron transfer (ConPET). The utility of this protocol is highlighted through the N-terminal modification of peptides and late-stage modification of drugs.