Human immunodeficiency virus (HIV) infection among injecting drug users remains a major health problem. Traditional approaches to prevent parenteral transmission of HIV infection in this population include abstinence facilitated through treatment for drug abuse, HIV testing with education and counseling, disinfection of needles with bleach between uses, and needle exchange programs. While each of these strategies are important and contribute to risk reduction, high-risk behavior and transmission of HIV infection continues. The development and distribution of safe and effective HIV vaccines in this population is urgently needed.