Protection against coastal disasters has been identified as an important service of mangrove ecosystems. Empirical studies on this service have been criticized, however, for using small samples and inadequately controlling for confounding factors. We used data on several hundred villages to test the impact of mangroves on human deaths during a 1999 super cyclone that struck Orissa, India. We found that villages with wider mangroves between them and the coast experienced significantly fewer deaths than ones with narrower or no mangroves. This finding was robust to the inclusion of a wide range of other variables to our statistical model, including controls for the historical extent of mangroves. Although mangroves evidently saved fewer lives than an early warning issued by the government, the retention of remaining mangroves in Orissa is economically justified even without considering the many benefits they provide to human society besides storm-protection services.