BACKGROUND & AIMS: Chronic hepatitis C increases mortality of patients with end-stage renal disease (ESRD). Ribavirin is not recommended for patients with renal dysfunction; peginterferon monotherapy is the most appropriate treatment for chronic hepatitis C in such patients. We evaluated the efficacy and safety of 2 dosages of peginterferon alfa-2a (40 kDa) in patients with chronic hepatitis C and ESRD on hemodialysis. METHODS: We performed a randomized, multicenter, open-label clinical study of 85 patients with chronic hepatitis C and ESRD who were receiving hemodialysis at specialist outpatient hepatology clinics. Patients were treated with subcutaneous peginterferon alfa-2a (40 kDa) at dosages of 135 or 90 mu g/wk for 48 weeks. RESULTS: The incidences of overall sustained virologic responses (SVRs) (undetectable hepatitis C virus [HCV] RNA [< 50 IU/mL] after 24 weeks of untreated follow-up) were 39.5% (15/38) in the 135 mu g/wk group and 34.9% (15/43) in the 90 mu g/wk group (odds ratio, 1.22; 95% confidence interval, 0.49-3.06; P = .67). Among patients with undetectable HCV RNA at week 12, 60.9% (14/23) of those in the 135 mu g/wk group and 87.5% (14/16) of those in the 90 mu g/wk group achieved an SVR. Therapy was well-tolerated with no new safety concerns. The most common adverse events (> 10% of patients in at least 1 treatment group) included conditions associated with ESRD (anemia and hypertension) and with interferon treatment. CONCLUSIONS: Forty-eight weeks of treatment with low-dose peginterferon alfa-2a (40 kDa) is safe and produces an SVR in 35%-40% of patients with chronic hepatitis C and ESRD on hemodialysis.