BACKGROUND & AIMS: The importance of histologic analysis of biopsy samples in the diagnosis and management of patients with autoimmune hepatitis (AIH) is unclear. METHODS: Patients with AIH were identified from a 10-year database. Individuals with overlap syndromes and decompensated liver disease were excluded. The proportion of patients who fulfilled the new simplified criteria for AIH was calculated. RESULTS: A total of 257 patients (203 female) with a median age of 52 years (interquartile range, 39-63 y) were diagnosed with AIH. Overall, 183 of 257 (71%) were positive for antinuclear antibodies, 116 (45%) had positive smooth muscle antibodies, and 29 of 257 (11%) were seronegative. A total of 250 (97%) patients had increased levels of autoantibodies and/or γ-globulins. In 95% (243 of 257 cases), the histology was compatible with AIH whereas 5% (14 cases) had atypical histology. Overall, 77% had a score of at least 6, indicating probable or definite AIH according to most recent criteria; 22% were diagnosed with AIH with less than 6 points and 1 patient had nonalcoholic steatohepatitis based on biopsy analysis. Immunosuppression occurred in 93% of patients. Patients with atypical versus compatible histology were similar in terms of seronegativity or γ-globulins; 86% (12 of 14) received immunosuppressive therapy despite atypical histology. CONCLUSIONS: Most patients with features of AIH, based on laboratory analyses, are likely to have a compatible liver histology. Few patients have atypical histology and these findings have little impact on patient management. These findings indicate biopsy samples might not need to be collected from patients who meet other clinical criteria for AIH.