Hepatitis C virus (HCV) infection is a serious public health problem, since 80% to 85% of HCV carriers develop a persistent infection that can progress into liver cirrhosis and hepatocarcinoma. Considering that the response of hepatitis C patients to combination therapy with interferon and ribavirin depends on HCV characteristics as well as on host features, we made a retrospective analysis of demographic and anthropometrical data and HCV genotype distribution of chronic hepatitis C patients treated in public and private reference centers in Brazil. The medical records of 4,996 patients were reviewed, 81% from public and 19% from private institutions. Patients' median age was 46 years, and there was a higher prevalence of male (62%) and white patients (80%). The analysis of HCV-infecting strains showed a predominance of genotype 1 (64%) over genotypes 2 and 3. The patients' mean weight was 70.6 kg, and 65% of the patients weighed less than 77 kg. Overweight and obesity were observed in 37.8% and 13.6% of the patients, respectively. Since a body weight of 75 kg or less has been considered an independent factor that significantly increases the odds of achieving a sustained virological response, the Brazilian population seems to have a more favorable body weight profile to achieve a sustained response than the American and European populations. The finding that 65% of chronic hepatitis C patients have a body weight of 77 kg or less may have a positive pharmacoeconomic impact on the treatment of genotype 1 HCV patients with weight-based doses of peginterferon.