Background: No prognostic score is currently available for long-term survival in autoimmune hepatitis (AIH) patients. Objective: The aim of this study was to develop and validate such a prognostic score for AIH patients at diagnosis. Methods: The prognostic score was developed using uni- & multivariate Cox regression in a 4-center Dutch cohort and validated in an independent 6-center Belgian cohort. Results: In the derivation cohort of 396 patients 19 liver transplantations (LTs) and 51 deaths occurred (median follow-up 118 months; interquartile range 60–202 months). In multivariate analysis age (hazard ratio [HR] 1.045; p < 0.001), non-caucasian ethnicity (HR 1.897; p = 0.045), cirrhosis (HR 3.266; p < 0.001) and alanine aminotra...