In 1999 a Swedish national expert panel published recommendations for the treatment of chronic hepatitis C (HCV) infection. Recently, pegylated interferon (peg-IFN) products have been introduced, and an increased knowledge concerning treatment of acute HCV and HCV-human immunodeficiency virus (HIV) coinfection has been gained. As a result of this, an update of the Swedish recommendations was developed following an expert meeting in October 2002. The panel now recommends the use of peg-IFN together with ribavirin as the standard treatment. Owing to the excellent response rates in HCV genotype 2 and 3 infections, these patients can be treated for 24 weeks without preceding liver biopsy. For patients with genotype 1 infection (with a slightly below 50% sustained response rate after 48 weeks treatment) and only mild histological disease, treatment can be postponed until future better treatment options become available. In patients who fail to achieve a 99% reduction (2 log drop) in viral titre after 12 weeks of treatment, discontinuation of therapy is recommended. Patients previously treated with IFN monotherapy and not having achieved a sustained virological response are recommended the same combination treatment as treatment-naive patients. IFN monotherapy is recommended in patients with acute hepatitis C. For children with chronic HCV infection, combination treatment is mainly recommended in clinical trials. For HCV-HIV coinfected patients, combination treatment is recommended and preferably given when blood CD4 counts are above 350/ml and before antiretroviral treatment (ART) is needed. Concurrent ART or prominent liver fibrosis requires frequent monitoring because of the increased risk for mitochondrial toxicity and liver failure.