WRISS was established using a hierarchical exclusionary model to capture weapon-related mortality and morbidity data for the five boroughs of New York City. Data were obtained from the New York City Vital Statistics Office, the New York State Hospital discharge database, Statewide Planning and Research Cooperative Systems, hospital emergency departments, and the police department. An evaluation of WRISS found it is a simple surveillance system that depends on both existing data sources and active data collection. The system is flexible and allows assault injuries without weapons to be added to better reflect domestic assaults. In addition, the system is efficient and cost- effective and is particularly suited to big cities with many assault injuries. Its low cost and obvious importance as a public health tool have allowed for its institutionalization. 3 references, 3 tables, and 1 figure