Background/Aim. The incidence of acute hepatitis B viral (HBV) infection in adults has increased in recent years in Serbia. Most icteric patients with acute hepatitis B resolve their infection and do not require treatment. Fulminant hepatitis B is a severe form of acute infection complicated by encephalopathy and liver failure. Subgroups of fulminant hepatitis B including hyperacute, acute and subacute are defined by the interval between jaundice and encephalopathy. Fulminant hepatic failure or subacute hepatitis B infection we observed in about 1% of all cases. In cases of fulminant hepatic failure or subacute form of HBV infection orthotopic liver transplantation can be life-saving operation, but in our country this procedure is difficult to achieve. Lamivudine has been established as a safe and effective antiviral agent for the treatment of chronic HBV hepatitis. Methods. In our pilot study performed at the Institute of Infectious and Tropical Diseases in Belgrade, Serbia in the period between 2002 and 2006 we treated 10 patients with clinically verified subacute HBV infection with lamivudine, 100 mg orally per day. Results. The most of the treated patients (9/10; 90%) survived subacute form of hepatitis B. After a few weeks of the treatment serum aminotransferase levels and other liver-function tests were normalized. Also, after a four-month lamivudine treatment all the patients lost HBsAg. Lamivudine was discontinued after six months in all the patients. In addition, six months after lamivudine was discontinued the patients remained well with normal results on liver-function tests. Conclusion. The obtained results suggest significant efficacy of lamivudine in patients with subacute hepatitis B. Also, we suggest that lamivudine therapy should be administered early in progression of subacute disease since it could be life-saving treatment in some patients, especially in the countries (like Serbia) where orthotopic liver transplantation is difficult to achieve.