Up to 60 patients with chronic hepatitis C genotype 1 infection who were previously treated with standard doses of peginterferon and ribavirin (1000 to 1200 mg daily) but who did not have a virological response (non-responders: n=35) or who relapsed after therapy (relapsers: n = 25) will be re-treated using peginterferon and higher doses of ribavirin (2000 to 2400 mg daily). After medical evaluation, documentation of eligibility and written informed consent, patients will be started on therapy with standard doses of peginterferon alfa-2a (180 micro g per week) and twice the standard dose of ribavirin (2000 mg daily for patients less than 75 kg; 2400 mg daily for patients greater than or equal to 75 kg). Viral kinetics will be evaluated on the basis of changes in HCV RNA levels during the first 24 weeks of therapy with blood sampling done on days 0, 1, and 2 and weeks 1, 2, 3, 4, 8, 12, 16, 20 and 24. Patients who fail to decrease levels of HCV RNA by more than 2 log(10) IU/ml by week 12 will be considered non-responders and therapy will stop. Similarly, patients who do not become HCV RNA negative (less than 10 IU) by week 24 will also be considered non-responders and therapy will be discontinued. Patients who do become HCV RNA negative during the first 24 weeks of therapy will continue for 48 weeks and be followed for at least 24 weeks thereafter. The primary end-point of this study will be a sustained virological response (SVR), which is defined by the absence of detectable HCV RNA in serum on treatment and for at least 24 weeks after stopping therapy. The SVR rate for re-treatment using conventional doses of peginterferon and ribavirin is expected to be less than 5 percent. The estimated rate of SVR using peginterferon with high doses of ribavirin is 50 percent for patients with a previous relapse and 25 percent for those with a previous non-response. A sample size of 35 patients would be needed to achieve statistical significance based upon these estimates of response rates for non-responders and 25 patients for relapsers. If none of the first ten non-responder patients treated in this protocol achieve an SVR, no more non-responder patients will be enrolled and this part of the study will be terminated early. Patients also will be monitored closely for side effects of therapy, the major one for ribavirin being anemia. Patients who develop anemia will be treated with darbepoietin to maintain a hemoglobin level above 10 gm percent. This pilot study is expected to demonstrate whether use of high doses of ribavirin is an option for patients who fail to have an adequate response to conventional doses of peginterferon and ribavirin for chronic hepatitis C.