A 24-year-old male without previously known comorbidities presented with progressive jaundice and hepatomegaly. Autoimmune serology and liver biopsy revealed features of autoimmune hepatitis. A treatment by oral prednisolone and azathioprine was initiated, after which he achieved remission. However, hyperbilirubinemia persisted, with a predominantly unconjugated fraction. Hemolytic causes of unconjugated hyperbilirubinemia were ruled out, and the diagnosis of Gilbert syndrome was established.