Abstract Background and aim The association between iron-metabolism-related variables and liver fibrosis in chronic hepatitis C and nonalcoholic fatty liver disease is now well known. However, the relationship has not been extensively studied in autoimmune hepatitis (AIH). We aimed to investigate the association between variables associated with iron metabolism and advanced liver fibrosis among untreated patients with AIH. Methods Ninety-seven untreated AIH patients were enrolled in this cross-sectional study. All participants underwent iron metabolism index detection and liver biopsy. Multiple logistic regression analysis was used to explore the association of iron-metabolism-related variables with advanced liver fibrosis. Results Among the 97 AIH patients, 38 (39.2%) had advanced liver fibrosis, and 59 (60.8%) did not. In multivariate logistic regression analysis, immunoglobulin G (odds ratio [OR], 1.123; 95% confidence interval [CI] 1.023–1.232, P = 0.014), platelet count (OR 0.988; 95% CI 0.979–0.997, P = 0.013), prothrombin time (OR 1.758; 95% CI 1.143–2.704, P = 0.010) and ferritin (OR 1.002; 95% CI 1.001–1.004, P = 0.012) were independent risk factors for predicting advanced liver fibrosis in AIH patients. Conclusion Higher serum ferritin was independently associated with advanced liver fibrosis among patients with treatment-naive AIH.