Among HIV-positive injection drug users (IDUs), we examined baseline predictors of lending needles and syringes and sharing cookers, cotton, and rinse water in the prior 3 months at follow-up. Participants were enrolled in Intervention for Seropositive Injectors-Research and Evaluation, a secondary prevention intervention for sexually active HIV-positive IDUs in 4 US cities during 2001-2005. The analyses involved 357 participants who reported injecting drugs in the prior 6 months at either the 6- or 12-month follow-up visit. About half (49%) reported at least 1 sharing episode. In adjusted analyses, peer norms supporting safer injection practices and having primary HIV medical care visits in the prior 6 months were associated with reporting no sharing of injection equipment. Higher levels of psychological distress were associated with a greater likelihood of reporting drug paraphernalia sharing. These findings suggest that intervention approaches for reducing HIV-seropositive IDUs' transmission of blood-borne infections should include peer-focused interventions to alter norms of drug paraphernalia sharing and promoting primary HIV care and mental health services.