Lamivudine is an oral nucleoside analogue with strong antiviral activity against hepatitis B virus. The HBeAg-negative patients tend to have lower serum HBV viral loads when compared to HBeAg-positive patients, but may develop liver disease. The objective of this study was to analyse the efficacy of lamivudine treatment of chronic hepatitis B patients negative in HBe antigen (HBe-Ag-negative). 102 patients were treated in Hospital of Infectious Diseases in Warsaw in the years 2001-2002. Patients were treated for 48 weeks with 100 mg lamivudine once daily (50 mg in case of renal failure). The end point of therapy of patients with chronic HBV infection negative for e antigen is more difficult to determine than for HBeAg-positive patients because HBeAg seroconversion marker cannot be applied. The only useful markers of therapy efficiency are the supression of HBV DNA replication and normalization ofALT activity level. Results at the end of therapy: normalization of ALT activity was observed in 48,7% patients, inhibition of viral replication was detected in 65,6% patients. The results are comparablewith known randomized clinical trials.