De novo autoimmune hepatitis (AIH) is a rare disorder first described in 1998. It occurs in patients who underwent liver transplantation for a different etiology. We present the case of a 56-year-old woman who was diagnosed with primary biliary cirrhosis and had liver transplantation for refractory pruritis. Seven years after transplantation, she presented alterations in the hepatic profile with hypertransaminasemia, elevated alkaline phosphatase and gamma-glutamyl-transferase. Her liver functions test also showed elevated IgG levels. Serum autoantibodies were negative except for antimitochondrial antibodies. Histological findings indicated features of AIH without bile duct damage or loss. She had a pretreatment AIH score of 13 points and a post treatment score of 15 points according to the International AIH Group. The patient was treated effectively with prednisolone and her liver function and globulin levels rapidly returned to normal.