BACKGROUND Dog bites that result in injuries occur frequently, but how frequently dog bite injuries necessitate medical attention at a hospital or hospital admission is unknown. OBJECTIVE To describe the incidence and characteristics of dog bite injuries treated in US emergency departments (EDs). METHODS Emergency department survey from the National Center for Health Statistics National Hospital Ambulatory Medical Care Survey for 1992 to 1994. METHODS National probability sample of patients visiting EDs. METHODS Incidence of dog bites treated in EDs, defined as a cause of injury recorded as the E-code E906.0. RESULTS The 3-year annualized, adjusted, and weighted estimate of new dog bite-related injury visits to US EDs was 333687, a rate of 12.9 per 10000 persons (95% confidence interval [CI], 10.5-15.4). This represents approximately 914 new dog bite injuries requiring ED visits per day. The median age of patients bitten was 15 years, with children, especially boys aged 5 to 9 years, having the highest incidence rate (60.7 per 10000 persons for boys aged 5 to 9 years). Children seen in EDs were more likely than older persons to be bitten on the face, neck, and head (73% vs 30%). We estimated that for each US dog bite fatality there are about 670 hospitalizations and 16000 ED visits. CONCLUSIONS Dog bite injuries are an important source of injury in the US population, especially among children. Improved surveillance and prevention of dog bite-related injuries, particularly among children, are needed.