Using a sample of supervisors from a Chilean retail company, we studied the effects of employees' role perceptions on three types of organizational citizenship behavior (OCB) and on their motivation to perform these behaviors. We recognized four types of motives: extrinsic, intrinsic, altruistic, and institutional. Results showed that when employees are externally motivated to perform OCB (by extrinsic or institutional motives), their motivation increases when they perceive the behaviors as in-role. However, when employees are internally motivated to perform OCB (by intrinsic or altruistic motives), their motivation is mostly independent of their role perceptions.