ObjectiveTo evaluate the effect of autoantibody on the efficacy and safety of pegylated interferonα-2a (Peg-IFNα-2a) and ribavirin on chronic hepatitis C (HCV). MethodsWe enrolled 106 chronic HCV infected patients, who were divided into autoantibody-positive group and negative group based on the baseline autoantibody detection. The patients were treated for 48 weeks. The anti-viral response and adverse effects were observed. Data analyses were reported using the SPSS 20.0 statistical package. ResultsThe prevalence of any autoantibody in chronic hepatitis C patients amounted to 31.1%, and serum anti-nuclear antibody was positive in 24 patients. Difference in age, sex, serum alanine transaminase level, aspartate transaminase level, total bilirubin level, thyroid function and HCV RNA level between autoantibody-positive group and negative group was not significant (P > 0.05). The level of hemoglobin in autoantibody-positive group was significantly lower than the negative group (P=0.018). Of the 106 patients, 82 patients achieved sustained virological response (SVR), 56 achieved rapid virological response (RVR), 98 achieved ealy virological response (EVR) and 8 were non-responders. There were no significant differences between RVR, EVR and SVR in autoantibody-positive group and negative group (P > 0.05). The most common adverse effects in this study were fatigue, weight loss, hair loss and fever, and no significant differences in adverse effects were observed between the two groups (P > 0.05). ConclusionAutoantibody positivity may not affect the treatment response and is safe in chronic HCV infected patients with combination therapy of pegylated interferonα-2a plus ribavirin.