This chapter examines the nature, contextual and dispositional antecedents, contingent behavioral consequences, and moderating effects of prosocial motivation at work. Prosocial motivation—the desire to protect and promote the well-being of others—is distinct from altruism and independent of self-interested motivations. Key antecedents include relational job design, collectivistic norms and rewards, transformational leadership, and individual differences in other-oriented values, agreeableness, and conscientiousness. Prosocial motivation more strongly predicts persistence, performance, and productivity when it is intrinsic rather than extrinsic; citizenship behaviors when it is accompanied by impression management motivation; and performance when manager trustworthiness is high. Prosocial motivation strengthens the relationships of intrinsic motivation with creativity, core self-evaluations with performance, and proactive behaviors with performance evaluations. Future directions include studying the conditions under which prosocial motivation fuels unethical behavior and harm-doing, collective prosocial motivation, behavior as a cause rather than consequence of prosocial motivation, new organizational antecedents of prosocial motivation, and implications for social entrepreneurship, corporate social responsibility, and the natural environment.