This article explores the relationship between precision attack and international humanitarian law. It begins by addressing the nature of precision attack, including precision technologies, the combat environment in which it occurs, attacker tactics, and the targeting process. Modern precision attack's greatest impact on international humanitarian law lies in four areas: indiscriminate attack; proportionality; precautions in attack; perfidy and protected status. The author concludes that precision warfare has both positive and negative implications for the interpretation and application of international humanitarian law on the twenty-first-century battlefield.