AIM: To evaluate health-related quality of life (HRQOL) in Chinese patients with chronic hepatitis C (CH-C), and the impact of antiviral treatment.METHODS: Short Form 36 (SF-36) Health-related Quality of Life Questionnaires to interview CH-C patients, and age- and sex-matched control subjects at outpatient clinics of a medical center in Taiwan were used. Data were transformed to scores for comparisons of eight major SF-36 domains. We also enrolled consecutive CH-C patients who completed one course of antiviral treatment(interferon α with ribavirin), and measured the HRQOLbefore, at the 12th wk of treatment, at the end of treatment, and at mo 6, after stopping the treatment to evaluate the impact of antiviral treatment.RESULTS: A total of 371 outpatients were enrolled, including 182 with CH-C and 189 age- and sex-matched subjects without CH-C. CH-C subjects had obviously lower educational status (P＜0.01). Mean scores of domains in general health, physical functioning, role-physical,role-emotional, vitality, and mental health of the SF-36 were significantly lower in subjects with CH-C than those without CH-C (P＜0.05). In an analysis of 47 CH-C patients who received and completed the whole course of antiviral treatment, mean scores of all domains were significantly lower at wk 12 of treatment compared to baseline. The scores returned to pretreatment values by the end of treatment, but were significantly increased at mo 6 after stopping the treatment. Among the 47 CH-C patients, 21 had sustained responses and 26 had nonsustained responses to antiviral treatment. Compared to pretreatment values, subjects with sustained responses had significantly lower social functioning scores at wk 12 of treatment, and scores for all SF-36 domains returned to pretreatment values, and increased significantly at mo 6 after stopping the treatment. For non-sustained virological responders, scores of all SF-36 domains significantly decreased at wk 12 of treatment, and did not increase significantly by the end of treatment, or at mo 6 after stopping the treatment when compared to the pre treatment values.CONCLUSION: HRQOL in CH-C patients is significantly impaired in most SF-36 domains. Antiviral treatment impaired HRQOL of CH-C subjects during early treatment, mainly in non-sustained virological responders, and improved at mo 6 after stopping the treatment, mainly in sustained virological responders.