Combination therapy with pegylated interferon and ribavirin is considered the new standard therapy for naïve patients with chronic hepatitis C. We evaluated the efficacy and safety of treatment with weight-based peginterferon alpha-2b (1.5 mg/kg per week) plus ribavirin (800-1,200 mg/day) for 48 weeks in naïve, relapser and non-responder (to previous treatment with interferon plus ribavirin) patients with chronic hepatitis C. Sixty-seven naïve, 26 relapser and 40 non-responder patients were enrolled. The overall sustained virological response (SVR) for the intention-to-treat population was 54% for naïve, 62% for relapser and 38% for non-responder patients. In the naïve subgroup, SVR was significantly higher in patients with the non-1 genotype (67%) compared to those with genotype 1 (45%). In relapsers and non-responders, SVR was, respectively, 69% and 24% in patients with genotype 1 and 43% and 73% in those with genotype non-1. There were no significant differences in SVR rates among the three body weight ranges (< 65 kg, 65-85 kg and > 85 kg) in any of the subgroups. Early virological response (EVR) was reached by 78%, 81% and 58% of naïve, relapser and non-responder patients, respectively, and among those with EVR, 63%, 67% and 61%, respectively, subsequently achieved SVR. All of the non-responder patients who did not have EVR reached SVR. Treatment was discontinued in 13% of the patients, due to loss to follow-up, hematological abnormalities or depression.