Antiviral therapy is aimed to persistently suppress hepatitis B virus (HBV) to prevent liver complications and improve survival and long-term administration of nucleos(t)ide analogues represents an attractive treatment strategy. Five oral analogues are available, and all inhibit viral replication in most patients during the first year of therapy. By converse, long-term monotherapy is associated to high rates of resistance with lamivudine, and intermediate rates with Adefovir and Telbivudine. Third-generation analogues such as Entecavir and Tenofovir may efficiently inhibits viral replication in most patient for many years as they couple potency and high genetic barrier. In patients developing drug-resistance, specific rescue protocols based upon 'early add-on' have been developed to rapidly and efficiently control viral replication. In cirrhotics, long-term effective analog-based therapy prevented clinical decompensation for many years, but not liver cancer development. Long-term administration of NUCs, either as a monotherapy or as a sequential combination, inhibits HBV replication in most HBeAg-negative patients for at least 5 years, preventing clinical decompensation in cirrhotics.