Drowning is a leading cause of unintentional injury death worldwide, and the highest rates are among children. Overall, drowning death rates in the United States have declined in the last decade; however, drowning is the leading cause of injury death among children aged 1-4 years. In 2001, approximately 3,300 persons died from unintentional drowning in recreational water settings, and an estimated 5,600 were treated in emergency departments (EDs). To update information on the incidence and characteristics of fatal and nonfatal unintentional drowning in the United States, CDC analyzed death certificate data from the National Vital Statistics System and injury data from the National Electronic Injury Surveillance System–All Injury Program (NEISS-AIP) for 2005-2009. The results indicated that each year an average of 3,880 persons were victims of fatal drowning and an estimated 5,789 persons were treated in U.S. hospital EDs for nonfatal drowning. Death rates and nonfatal injury rates were highest among children aged ≤4 years; these children most commonly drowned in swimming pools. The drowning death rate among males (2.07 per 100,000 population) was approximately four times that for females (0.54). To prevent drowning, all parents and children should learn survival swimming skills. In addition, 1) environmental protections (e.g., isolation pool fences and lifeguards) should be in place; 2) alcohol use should be avoided while swimming, boating, water skiing, or supervising children; 3) lifejackets should be used by all boaters and weaker swimmers; and 4) all caregivers and supervisors should have training in cardiopulmonary resuscitation.