ABSTRACT— Hepatitis B virus DNA (HBV-DNA) in serum was studied in 67 anti-HBe patients using dot-blot hybridization, a modified technique and polymerase chain reaction (PCR). All patients had abnormal aminotransferase (ALT) levels. Serum HBV-DNA was detected in 14/67 cases by dot-blot and in 39/67 (DNA probe) and 45/67 (RNA probe) using the modified technique. The RNA probe was more sensitive than the DNA probe when they were compared, using serial dilutions of HBV-DNA of known concentration (0.1 pg vs 1 pg, respectively). HBV-DNA was found by PCR in 57/67 patients. Ten patients were negative to serum HBV-DNA. The ALT level was significantly higher in patients with serum HBV-DNA by dot-blot as compared to those who had serum HBV-DNA by the modified technique and PCR. With respect to the presence of anti-HCV, 6/67 had anti-HCV confirmed by RIBA test. These 6 patients had serum HBV-DNA. The route of acquisition of HBV infection in anti-HCV positive patients was by parenteral exposure in 67% of the cases and 15% in HCV negative (p<0.05). All patients were negative to nonorganic specific autoantibodies. In summary, most of the anti-HBe patients (85%) had viral replication. HCV superinfection plays a minor role in the activity of liver disease.