Abstract Background Hepatocellular carcinoma (HCC) in autoimmune hepatitis (AIH) was considered rare but is increasing with prolonged prognosis. Its impact on the overall prognosis of AIH is unknown, and treatment has not been established. Aim To investigate the risk factors and prognosis of HCC in patients with AIH and identify appropriate management strategies. Methods We studied patients with AIH including background liver disease, sex, age, complications, treatment, response to treatment, liver fibrosis, prognosis, and treatment. Results In 131 patients, deaths due to liver failure were more common early after the onset of AIH; however, deaths due to HCC increased gradually. HCC was observed in 12 patients (median age, 70 years; male/female, 4/8; cirrhosis at onset, 11; median time to carcinogenesis, 7 years). Cirrhosis at diagnosis was identified as a risk factor for carcinogenesis in the multivariate analysis (odds ratio, 41.36; p