Hepatitis C virus (HCV) infection refractory to previous therapy is common. Treatment of patients with refractory disease is difficult and less studied. Pegylated interferon alpha-2b plus ribavirin is used for treatment of HCV patients naïve to therapy. We conducted a randomized study for refractory HCV patients using a high- vs. a low-dose pegylated interferon alpha-2b and ribavirin protocol. Our aim was (1) to determine the efficacy of pegylated interferon alpha-2b plus ribavirin to eradicate HCV in previously treated individuals and (2) to compare a low-dose to a high-dose regimen. One hundred fifty-two patients were initiated in the study, 112 (74%) were male and 40 (26%) female. Nineteen percent of patients obtained a sustained viral response (SVR) in the high-dose arm. Prior relapsers had the highest SVR rates: 50% in non-genotype 1 and 34% in genotype 1. The odds of achieving a SVR were six times higher in previous relapsers. The rate of SVR in genotype 1 patients who were nonresponders to prior therapy was only 8%. All patients who achieved a SVR had no detectable virus at week 24. However, only half of those who had undetectable viral titers at week 24 achieved a SVR. In conclusion, retreatment of patients with refractory hepatitis C infection with interferon alpha-2b and ribavirin combination therapy is well tolerated and gives modest response rates. The most important factor in predicting response to therapy is the manner of response to previous treatment. The likelihood of response to treatment can be predicted from the viral titers at 24 weeks.