In therapy of chronic hepatitis B, there are new and exciting developments in antivirals such as nucleotide analogues. Adefovir dipivoxil is an oral prodrug of adefovir, a nucleotide analogue of adenosine monophosphate. This agent has a potent in vitro and in vivo effect against herpes virus, retroviruses, and hepadnaviruses. In the hepatitis B virus (HBV) setting, adefovir dipivoxil inhibits both the wild type and lamivudine-resistant HBV strains. The safety profile of adefovir dipivoxil 10 mg is excellent, but higher doses can produce renal tubular damage, particularly when the drug is used for prolonged therapy. Adefovir dipivoxil is an important new addition to the current first-line treatments for HBeAg positive and negative chronic hepatitis B, as well as being rescue therapy for lamivudine-resistant HBV strains. It is also licensed for use in adults with decompensated liver disease, as well as compensated liver disease where there is evidence of active viral replication, persistently elevated serum alanine aminotransferase levels and active liver inflammation and fibrosis. However, a longer follow-up is needed to establish the long term safety and efficacy of adefovir dipivoxil in patients with chronic HBV infection.