The effects of chronic hepatitis C virus (HCV) infection, in the absence of cirrhosis, on patients' quality of life was assessed using the short form 36 (SF36) symptomatology questionnaire. Patients with chronic hepatitis C were polysymptomatic and had significant reductions in their SF36 scores for all of the modalities tested. Patients with chronic hepatitis B virus (HBV) infection showed a reduction in the SF36 scores that assessed mental functions, but they had no decrease in the scores that measured physical symptoms, indicating that the symptoms associated with chronic HCV infection are qualitatively different from those associated with chronic HBV infection. Patients with chronic HCV infection who had used intravenous drugs in the past had the greatest impairment in quality-of-life scores, but the reduction in quality-of-life scores was still found in patients who had never used drugs. The reduction in quality of life could not be attributed to the degree of liver inflammation or to the mode of acquisition of the infection. Hence, chronic infection with HCV per se gives rise to physical symptoms that reduce the quality of life of infected patients.