E codes classify causes of injury as unintentional, intentional, and undetermined. E-coded discharge data from hospitals provide an opportunity to use this source of morbidity data for planning, implementation, and evaluation of injury and violence prevention activities. This study explores the extent to which E-coded data from hospitals identify injuries that result from violent acts. Cases were identified through a multihospital population-based surveillance system of pediatric injuries. Those cases with injury as a result of violence, designated by study criteria, were compared with those with E codes that were classified as intentional. The analysis indicated that 25 percent of injuries to children resulting from violence may not be accounted for through the use of E codes. The majority of the undetected injury cases resulting from violence involved child abuse. Researchers and other persons who design and conduct injury and violence prevention programs should be aware of the undercount and associated issues when using E-coded hospital discharge data for surveillance of injuries resulting from violence.