Résumé : Aim: To compare responses to therapy of Black African (BA) and non-Black African (non-BA) patients with hepatitis C virus genotype 4 (HCV-4) residing in Belgium. Methods: In this retrospective multicenter study, 473 patients with HCV-4 were selected from databases at 7 Belgian centers; 209 treatment-naïve patients (154 BA) had received treatment with peg-interferon (peg-IFN) plus ribavirin (RBV) and were included in the study. Results: There was a greater percentage of female patients in the BA group than in the non-BA group; BA patients were also older, had a greater body mass index, and more frequently had abnormal glucose metabolism. The route of contamination was more frequently unknown in BA than in non-BA patients and BA patients had more HCV-4 subtypes. There were no differences in other demographic factors between the groups. Sustained viral response (SVR) and complete early viral response rates were significantly lower and relapse rates significantly higher in BA than in non-BA patients. There were no differences between groups in rates of dose modification or in drug tolerance. Conclusion: In our cohort, treatment-naïve BA patients with HCV-4 who were treated with peg-IFN and ribavirin had a much lower SVR rate than treatment-naïve non-BA patients with HCV-4 who were treated with peg-IFN and ribavirin, and a higher relapse rate, possibly related to a weaker response to interferon-based therapy. Treatment may need to be adapted in this population.