AbstractThis study was the first to link a functional view of organizational citizenship behavior (OCB) to intrinsic and extrinsic motivation. Citizenship behavior and motives were assessed along with motivational orientation and prosocial personality. The results suggest that motives, and the types of OCB they foster, derive in part from individual differences in motivational orientation. Intrinsically motivated individuals manifested internal, other‐oriented motives for OCB, while those with extrinsic orientations were driven largely by external, self‐focused objectives. Mediation analyses implicated motivational orientation as a causal factor in determining specific motives. Citizenship activities directed at coworkers also showed a strong relationship with prosocial personality. A strong, positive correlation between intrinsic and extrinsic motivation suggested the usefulness of viewing them as complementary rather than competing tendencies, working together to help individuals accomplish a goal. The data further highlight the efficacy of a functional approach to understanding a broad spectrum of prosocial actions.