Intravenous drug abuse is strongly associated with HIV transmission and with having a diagnosis of Antisocial Personality Disorder (ASPD). While the co-occurrence of intravenous drug abuse and ASPD is related to poor drug abuse treatment outcome, little is known about the contribution of ASPD to the intravenous drug abusers (IVDAs) level of HIV risk. The present study related the diagnosis of ASPD with specific drug use behaviors associated with high risk of HIV transmission. Subjects (N = 100) were intravenous drug abusers who volunteered for an HIV risk assessment study. Subjects with ASPD reported significantly higher rates of injection-equipment sharing and shared with significantly more people than IVDAs without ASPD.