Soft tissue infections (STIs), including abscesses and cellulitis, are a common complication of injection drug use. In 1997, 54 (32%) of 169 injection drug users (IDUs) in one San Francisco neighborhood had a drug-injection-related abscess or cellulitis (1). To characterize STIs among IDUs, data from San Francisco General Hospital (SFGH) discharge and billing records were analyzed. This report summarizes the results of that analysis and presents the case report of one IDU with an STI. The findings indicate that STIs are among the most common diagnoses among patients admitted to SFGH. Preventing STIs among IDUs in San Francisco will require coordinated action involving health-care providers, public health agencies, substance abuse treatment, community outreach, syringe exchange programs, IDUs, and community-based organizations.