Objectives: A non-invasive, simple and non-expensive test to predict cirrhosis would be highly desirable. The aspartate aminotransferase/ alanine aminotransferase (AST/ALT) ratio has been proven to be such an indicator of cirrhosis in alcoholic liver disease, hepatitis C. Aim: To test whether the AST/ALT ratio is a marker of cirrhosis also in patients with primary biliary cirrhosis (PBC). Methods: The study consisted of 160 patients. In 126 patients, we had clinical and laboratory data at the time of diagnosis and follow-up with outcome: liver-related death, liver transplantation and survival. In 121 patients, we had laboratory data and liver histology. Results: We found that the AST/ALT ratio was significantly higher in cirrhotic patients than in non-cirrhotic patients. A high AST/ALT ratio was significantly associated with esophageal varices and ascites. In a multivariate analysis, bilirubin and ALP were predictors of poor prognosis. Conclusion: The AST/ALT ratio seems to be of clinical value as a hint to the diagnosis of cirrhosis in patients with PBC but not as a prognostic factor. © 2006 Blackwell Munksgaard.