Coinfection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) is common as a result of shared routes of transmission, especially in high-risk groups such as injection drug users and persons with hemophilia. HIV is known to influence the natural history of HBV, hastening progression to end-stage liver disease and cirrhosis. Antiretroviral therapy for HIV, and associated immune reconstitution, may result in immune-mediated liver damage as HBV-infected hepatocytes are targeted. This can lead to liver enzyme elevations that may be misattributed to drug-related toxicity. Thus, it is important that HIV-infected patients be tested for HBV and that clinicians be aware of the possibility of atypical serologic markers of HBV in HIV-infected patients. In managing coinfected patients, control of HIV is the priority. In patients with controlled HIV who are candidates for HBV therapy, the goals are the same as in the HBV-monoinfected population: hepatitis B e antigen seroconversion, liver enzyme normalization, and HBV DNA suppression. Treatment options include interferon-based regimens, lamivudine, adefovir, tenofovir, and entecavir. All of these agents have been shown to be relatively effective in HBV-monoinfected patients. However, few randomized, controlled HBV treatment trials have been conducted in coinfected subjects, and thus additional studies are warranted.