Chronic hepatitis B is an important public health problem worldwide. In Poland the incidence rate decreased from 40,0 (in the year 1990) to 3,86 (in 2004) per 100,000 inhabitants. The goal of anti-chronic hepatitis B therapy is to prevent the progression of liver disease to cirrhosis which may effect in development of liver failure or HCC. The aims of treatment are: reduction of HBV viral load and normalization of ALT activity. Among HBeAg positive patients important marker is the loss of e antigenemia followed by seroconversion to anti-HBe positivity. Lamivudine is an oral nucleoside analogue with strong antiviral activity against hepatitis B virus. The objective of this study was to analyse the efficacy of lamivudine treatment of chronic hepatitis B patients positive for hepatitis B e antigen (HBeAg). 224 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). Results obtained at the end of therapy: loss of HBeAg was observed in 33,4% and seroconversion to anti-HBe in 15,1% patients, normalization of ALT activity was noticed in 53,4% patients, inhibition of HBV DNA replication was observed in 37,9% patients. The results are comparable with known randomized clinical trials.