Pedunculated hepatocellular carcinoma is an unusual form of hepatocellular carcinoma protruding from the liver with or without a pedicle. We present a case of pedunculated hepatocellular carcinoma misdiagnosed as right adrenal tumor on MRI and FDG PET/CT. Intraoperative exploration revealed the mass was attached to the liver, but the right adrenal gland was intact. Laparoscopic biopsy revealed poorly differentiated hepatocellular carcinoma. This case indicates it may be difficult to diagnose pedunculated hepatocellular carcinoma because it is hard to define its origin on imaging. Elevated alpha-fetoprotein level and a history of viral hepatitis may be helpful for the diagnosis.