Ustekinumab is a fully human monoclonal antibody that binds to interleukin (IL)-12/23. Ustekinumab-related liver injury (UST) is rare. There is limited data available on the potential for ustekinumab-liver interaction. We report the case of a patient from our institution followed for colitis ulcerative who developed autoimmune hepatitis (AIH) during treatment with ustekinumab. The diagnosis of autoimmune hepatitis was retained on the simplified criteria for autoimmune hepatitis. Therapeutic management consisted of stopping ustekinumab and starting corticosteroids and immunosuppressants, with regression of cytolysis at 2 months. The purpose of the article is to alert readers and encourage them to report similar cases for better knowledge of the drug.