Patients with chronic hepatitis C virus (HCV) infection vary in their rates of fibrosis progression. The renin-angiotensin system (RAS) regulates fibrosis. Polymorphisms in the genes of the RAS may contribute to the outcome of renal and cardiovascular disease. We studied four RAS gene polymorphisms in 195 patients with chronic HCV infection. Patients were grouped by Ishak stage of fibrosis on liver biopsy: group 1 (fibrosis score 0 or 1; n = 97), group 2 (fibrosis score 2 or 3; n = 73) and group 3 (fibrosis score 4-6; n = 25). Polymorphisms of the angiotensinogen (AGT) gene (M235T and AT-6), the angiotensin I converting enzyme gene and the type 1 angiotensin II receptor gene were assayed. There was no difference in the distribution of these polymorphisms of the RAS between the fibrosis groups. There did not appear to be any increased prevalence of fibrosis if two or even three of the polymorphisms associated with increased RAS effect were present. On multivariate analysis factors significantly associated with fibrosis were necroinflammatory activity (P < 0.001) and age (P < 0.001). No association was identified between these four RAS polymorphisms and fibrosis in chronic HCV infection.