Chronic hepatitis B virus (HBV) infection affects > 350 million individuals worldwide. Chronic hepatitis B is associated with complications of end-stage liver disease, including cirrhosis and hepatocellular carcinoma. HBV replication is the best predictor of liver disease progression to cancer, and antiviral therapy may diminish or halt this unfavorable outcome. Six drugs have been approved for the treatment of chronic hepatitis B: interferon-α_2b, pegylated interferon-α_2a, lamivudine, adefovir, entecavir and telbivudine. Most agents designed to target hepatitis B are hindered by the development of resistance, poor tolerability or limited efficacy; therefore, new agents and treatment strategies are needed. Telbivudine is the latest approved anti-HBV agent; it is an orally administered nucleoside analog that selectively inhibits HBV replication. It has demonstrated potent activity against HBV in Phase III clinical studies, with good tolerance, lack of mitochondrial toxicity and no dose-limiting side effects.