Hepatitis B surface antigen (HBsAg) is regarded as sole marker of hepatitis B virus (HBV) infection in Bangladesh and most other developing countries. However, some HBV-negative subjects may harbor HBV DNA and transfusion of their blood may cause HBV infection in recipients. HBV DNA was checked in 20 patients with cryptogenic liver cirrhosis, 10 patients with hepatocellular carcinoma without any known etiology, and 10 apparently healthy subjects with elevated levels of serum alanine aminotransferase (ALT). HBV DNA was detected in 8 of 20 patients with cryptogenic liver cirrhosis, 1 of 10 patients with hepatocellular carcinoma, and 2 of 10 apparent healthy subjects with elevated ALT. However, all of them were negative for HBsAg in the sera.