Context.-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). Design.-Emergency department survey from the National Center for Health Statistics National Hospital Ambulatory Medical Care Survey for 1992 to 1994. Patients.-National probability sample of patients visiting EDs. Main Outcome Measure.-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 333 687, a rate of 12.9 per 10 000 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 10 000 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.