The seroepidemiology of HBV and HCV infections in the patients with acute and chronic liver diseases in Jakarta was investigated. The sera from 141 cases with acute hepatitis, 176 liver cirrhosis and 70 hepatocellular carcinoma (HCC) were exmained. Anti-HA IgM, HBsAg, antiHBc IgM and anti HCV (Ortho) were detected by Elisa method. In acute hepatitis, 83 cases (58.9%) out of 141 cases were hepatitis A and 9 cases (6.4%) hepatitis B. The others were diagnosed non-A, non-B (NANB) hepatitis and anti-HCV in 4 cases (11.8%) out of 34 cases with NANB hepatitis was positive. The low prevalence of antiHCV in acute NANB hepatitis seems to be due to inadequate date of serum sampling. HBsAg and anti-HCV in liver cirrhosis were positive 36.5% and 73.9% respectively, including 22.7% of double infection. HBsAg and anti-HCV in HCC were 58.6% and 34.2%, including 17.1% of double infection. In 16.7% fo chronic liver disease (liver cirrhosis and HCC), neither HBsAg nor anti-HCV were detected.