Hepatitis B virus (HBV) is a common coinfection in HIV-infected patients, and significant liver disease and mortality occur as the result of this disease combination. Potent anti-HBV therapy is available and can be used to improve outcomes by suppressing HBV DNA. Many HBV agents have dual activity with HIV and may be used to treat both diseases. However, care must be taken when using HBV nucleos(t)ides that have not been fully studied in the HIV-infected population because the emergence of strains resistant to HIV treatment has been reported. Careful monitoring of response to treatment is needed when treating an HIV/HBV patient with severe immune suppression. Improved ability to obtain long-term HBV DNA suppression and avoid resistance will translate into improved survival in this population.