Résumé : Background and study aims: PROPHESYS was a prospective, international cohort study of monoinfected, treatment-naive chronic hepatitis C patients treated with a combination of peginterferon alfa-2a or alfa-2b and ribavirin. It included worldwide 7,163 patients from 19 countries (including 384 patients from Belgium alone) and demonstrated that sustained virologic response rates in the real world were similar to those achieved in well-controlled clinical trials. The objective of this sub-analysis was to present an overview of the baseline characteristics, anti-hepatitis C drug treatment, and virologic responses of the patients treated in Belgium, infected with HCV genotype 1, 2, 3, or 4, and administered peginterferon alfa-2a. Moreover, the impact of ribavirin dosage on the response to treatment was studied. Patients and methods: 356 patients were included in this subanalysis. All variables were summarized using descriptive statistics. Results: Compared to the published data of the whole study population (1), the Belgian data presented some significant differences in terms of genotype distribution and response to treatment (e.g. lower prevalence of HCV genotype 1 infection, lower virologic response rates in HCV genotype 2 patients). Deviations from existing recommendations were identified (e.g. higher dose of ribavirin in HCV genotype 2 or 3 patients). Patients who received less than 80% of the target dose of ribavirin experienced a significantly weaker response to treatment. Conclusion: This sub-analysis provided an interesting profile of the Belgian experience in the treatment of chronic hepatitis C.