Background/Aims: Hepatitis B virus (HBV) is associated with clinically significant chronic infection that may lead to the development of cirrhosis or even hepatocellular carcinoma. However, interferon alpha is effective in only 25-40% of chronic hepatitis B patients. The purpose of this study was to evaluate the effectiveness of interferon and lamivudine combination treatment comparing with interferon alone. Methods : Twenty patients with chronic hepatitis B(moderate to severe activity) were randomized to with interferon alone (11 patients) or combination (9 patients) therapy for 24 weeks. The patients were monthly evaluated, biochemically and serologically. Results : There was no statistical difference between both groups in HBeAg seroconversion rate and ALT normalizaion rate at the end of treatment. But, HBV DNA suppression rate was significantly higher in combination group (100%) than the interferon alone group (54%). No serious side effects were noted in both groups. Conclusion : Combinaton therapy with alpha interferon plus lamivudine given for 24 weeks appears safe and is well tolerated. But, combination therapy was no more efficient than interferon alone in HBeAg seroconversion except HBV DNA suppression rate during the treatment period.