This study investigated relations between 3 work-related stressors (role ambiguity, role conflict, and organizational constraints) and altruistic behavior in the workplace. It was predicted that each stressor would be negatively related to altruism and that these relations would be moderated by affective commitment (AC). Data from 144 incumbent-supervisor dyads revealed that all 3 stressors; were weakly and negatively related to altruism. Two of these relationships were moderated by AC, although not as predicted. Organizational constraints were positively related to altruism among those reporting high levels of AC but negatively related among those reporting low levels of AC. The pattern was exactly opposite for role conflict. Implications of these findings are discussed