Comprehensive, population-based surveillance for nonfatal injuries requires uniform methods for data collection from multiple hospitals. To show issues related to design and implementation of multihospital, emergency department (ED), injury surveillance, a city-wide system in the United States is discussed. From October 1, 1995 to September 30, 1996 all injury-related ED visits among District of Columbia residents <3 years of age were ascertained at the 10 hospitals where city children routinely sought care. Information was abstracted from 2,938 injury-related, ED visits (132.7 visits/1,000 person-years). Based on this experience, suggestions to facilitate design of multihospital, injury surveillance in other locations are offered. Importantly, injury-related visits were reliably ascertained from ED logs, and for most variables, a systematic sample of injury-related visits was representative of the total injured population. However, there is a need for more complete documentation of circumstances surrounding injuries and for standardization of data elements on ED logs and treatment records.