The aim of this study was to assess the long-term outcome in hepatitis B virus (HBV)-infected patients according to HBV, hepatitis C virus (HCV), and hepatitis D virus (HDV) replication, focusing on survival, liver failure, and hepatocellular carcinoma (HCC). A cohort of 302 hepatitis B surface antigen (HBsAg)-positive subjects (mean age, 34 +/- 15.3 years; male/female 214/88; 39 subjects under 14 years) with biopsy-proven chronic hepatitis (86 with cirrhosis) was prospectively assessed, with a median follow-up of 94 +/- 37.6 months. One hundred nine patients received interferon alfa (IFN). At baseline, 86 subjects (28.5%) were hepatitis B e antigen (HBeAg)-positive (wild-type HBV), 80 (26.5%) were HBeAg-negative, HBV-DNA-positive, 76 (25.2%) had HDV infection, 43 (14.2%) had dual HBV/HCV infection, and 17 (5.6%) were negative for HBV-DNA, anti-HCV, and anti-HDV. During follow-up, decompensation of disease occurred in 46 subjects: 8 developed HCC, 36 developed ascites, and 2 developed jaundice. Five patients underwent transplantation. Thirty-five subjects died: 33 of hepatic and 2 of nonhepatic causes. Overall mortality was 5.2-fold that of the general population (95% CI: 3.6-7.3; 35 deaths observed, 6.7 expected; P <.0001). By Cox regression analysis, survival was independently predicted by young age, absence of cirrhosis at baseline, and sustained normalization of aminotransferases during follow-up. Survival without decompensation was independently predicted by the same factors and by IFN treatment. Chronic hepatitis B infection increases mortality in comparison with the general population in our area regardless of specific virological profiles at presentation. Presence of cirrhosis and persistent necroinflammation markedly increase the risk of death.