The aims of this study were to assess baseline predictive factors associated with early virologic response (EVR) and sustained virologic response (SVR) in patients with chronic hepatitis C treated with pegilated interferon alpha and ribavirin. This retrospective study included 98 patients with chronic hepatitis C treated with individualized weight-based dosing regimen for pegilated interferon alpha and ribavirin on an out-patient basis between January 2001 and January 2006. The patients had been naive or previously treated with standard interferon and ribavirin. The patients with genotype 1 and 4 were treated for 48 weeks and patients with genotype 2 and 3 were treated for 24 weeks. Virological response rates at different weeks were investigated, with EVR defined as serum HCV RNA undetectable or decrease by >/ = 2 log (10) after 12 weeks and SVR defined as HCV RNA undetectable at week 24 of follow-up. We investigated the predictive value of baseline age, gender, body-mass index, fibrosis score, histopathologic activity index , HCV genotype, titers of HCV RNA, alcohol abuse, serum ALT levels, pegilated interferon and/or ribavirin dose reduction, relaps after a course of standard interferon and ribavirin on SVR in HCV infected patients treated with pegilated interferon alpha and ribavirin. Early virologic response was achieved in 84 % (in 82 of 97 patients with chronic HCV infection) of and SVR in 59 % (in 34 of 84 patients with chronic HCV infection) patient. In univariate analysis, gender were associated with SVR. From multivariate logistic regression analysis of all patients, we did not found independent predictors for SVR and EVR. The SVR rates (72 %) of patients who had achieved EVR were significantly higher than those (10 %) of patients who had not achieved EVR (P < 0.005). The negative predictive value of an early virological response at week 12 on SVR was 90 %. Our results indicate quantitative virological assessment after 3 months may identify patients who are more likely to reach SVR.