The lifetime cumulative risk of developing cirrhosis and hepatocellular carcinoma is the rationale for treating patients with chronic hepatitis C with antivirals. The standard treatment is combination therapy with interferon-alfa and ribavirin. In patients with high transaminases and histologic signs of chronic hepatitis, 6- to 12-month therapy with 3 mega units (MU) interferon-alfa thrice weekly, combined with ribavirin, yielded up to 30% sustained responders, and this was increased to 50% with pegylated interferon combined with ribavirin. Favorable predictors of response to the former treatment were genotype 2 or 3, less than 2 million copies of hepatitis C virus (HCV), no portal fibrosis at biopsy, age less than 40 years, and female sex. The same was true for the latter treatment; however, with body weight less than 82 kg replacing female sex. A 98% cure of community-acquired acute hepatitis C was achieved with early treatment with daily doses of 5 MU interferon, compared with a calculated 30% HCV-RNA clearance in untreated patients. More cost-effective strategies for ceasing treatment, based upon early clearance of HCV, are under investigation, with cutoff equal to or more than a 2 log decrease in serum HCV-RNA at week 12. This approach has 100% negative predictive value and 80% positive predictive value. Treatment can also be optimized by combination retreatment of relapsers and nonresponders to monotherapy, which yielded sustained responses of 50% and 25%, respectively. There are difficult-to-treat patients who have high viremia, genotype 1 and 4, or coinfection with HIV or HBV, or carry an organ graft, and those who did not respond to combination therapy. Extended treatment of the latter patients with pegylated interferon might slow down the progression of fibrosis.