The aim of this study was to evaluate the importance of different endogenous and exogenous factors associated with cirrhosis development among hepatitis C virus (HCV)-positive individuals from an area of low prevalence. We studied 106 consecutive HCV RNA positive patients who had undergone liver biopsy. Each patient was assessed with special attention to risk factors for hepatitis C infection, average daily alcohol consumption and analysis of plasma levels of alpha1-antitrypsin (alpha1AT) and alpha1-antichymotrypsin (alpha1ACT). Viral RNA, amplified from serum with the polymerase chain reaction (PCR) technique, was used for genotyping. Liver biopsies were assessed according to conventional histopathological criteria, and for necroinflammatory activity (grade) and fibrosis (stage) according to a numerical scoring system. The presence of cirrhosis (stage 4) was used as the dependent variable in multivariate logistic regression analysis. Alcohol abuse (P = 0.007), age at entry (P < 0.001), immigrant status (P = 0.017) and a low alpha1ACT level (P = 0.008) were all independent determinants of progression to cirrhosis whereas HCV genotype 1, estimated duration of HCV infection and positivity for antibodies to hepatitis B core antigen (HBcAb) were not. Cirrhosis occurred at a significantly younger age (P = 0.00(5) among alcohol abusers. Hence, both endogenous and exogenous factors such as subnormal alpha1ACT levels and alcohol appear to contribute to the rate of progression to cirrhosis among HCV-positive patients.