Why states comply with international law has long been at the forefront of international law and international relations scholarship. The compliance discussion has largely focused on negative incentives. We argue that there is another, undertheorized mechanism: Rewarding. We provide a typology and illustrations of how rewards can be applied. Furthermore, we explore the rationale, potential, and limitations of rewarding, drawing on rationalist and psychological approaches. Both approaches provide ample justifications for making greater use of rewarding in international law.