In the United States, approximately 25% of the 40,000 new human immunodeficiency virus (HIV) infections each year are secondary to injection drug use. Worldwide, there are an estimated 12.6 million injection drug users, and 10% of HIV infections (420,000 infections in 2003) are associated with this practice. Buprenorphine is a new medication used to treat opioid dependence that shows promise for reducing the rate of HIV transmission and improving the care of opioid-dependent patients with HIV infection. Although buprenorphine faces fewer clinical and regulatory barriers than does methadone, the optimal strategy for integration of office-based treatment of opioid dependence and HIV disease is an area of ongoing research. This review addresses the introduction of buprenorphine, in terms of public health, policy, and clinical implications for HIV-infected patients and for HIV care providers.