This study compares the sociodemographic characteristics and human immunodeficiency virus (HIV) risk behaviors of injection drug users who had received drug abuse treatment in the previous 5 years and those who had not received treatment. The National AIDS Demonstration Research Program database provided 2001 structured interviews, representing Cleveland, Columbus, Cincinnati, and Dayton, Ohio. About 43% of the subjects reported having received treatment in the previous 5 years. Length of involvement with drugs, more frequent injection, more legal problems, and higher levels of HIV risk behaviors were associated with a history of treatment. Incorporating HIV risk reduction education in drug abuse treatment is an urgent priority.