Despite the wealth of scientific findings showing that needle exchange programs reduce unsafe injection practices and that these practices are the direct or indirect cause of one-third of new HIV infections in the United States, the future of needle exchange in this country remains uncertain. The Federal Government continues to ban the use of federal funds to support needle exchange programs and State and local officials continue to oppose implementation of exchange services. This study analyzed closure of a well-established needle exchange program. It examined the claimsmaking that succeeded in defining the needle exchange as a public health hazard and a social problem, resulting in its closure after several years of operation. The study analyzed the impact of the closure, based on initial and follow-up interviews with needle exchange clients, surveys of public drug-using sites and ethnographic interviews. Tables, figure, references