We present a case of a 16-year-old adolescent boy with autoimmune pancreatitis and a review of the related literature. The patient was sent from a peripheral medical center, presenting with jaundice, pruritus, weight loss, and hyperglycemia of 20 days' duration. At admission, the patient was icteric, choluric, and acholic. His abdomen was soft and nontender, and the patient felt no pain in his abdomen. He had skin lesions because of scratching. Laboratory findings showed a blood glucose level of 135 mg%; total serum bilirubin, 29.4 mg%; direct bilirubin, 23 mg%; and alkaline phosphatase, 1100 IU/L. Abdominal ultrasound showed an enlarged head of the pancreas that was 30 x 35 mm. The parenchyma was slightly heterogeneous. Abdominal computed tomography showed an enlarged head of the pancreas with a normal body and tail, thickened duodenal wall, and dilated intra- and extrahepatic biliary tract, and the distal choledochus was not visible. Magnetic resonance imaging showed dilated intra- and extrahepatic biliary tract. The choledochus was not visible, and the cystic duct ended abruptly. The pancreas head was enlarged and homogenous, and there were no changes with contrast. Wirsung's duct was not dilated. Laparotomy was performed with a presumed diagnosis of pancreatic head tumor. The pancreas was diffusely indurated and enlarged; biopsy and intraoperative cholangiography were performed. The biliary tract was dilated with no duodenal passage of contrast, and the Wirsung's duct was not observed. Cholecystectomy was performed, and a transcystic drain was positioned. The histopathology was compatible with autoimmune pancreatitis. Prednisone treatment was started with good response. Autoimmune pancreatitis is a very rare entity among children and adolescents. It should be suspected when characteristic clinical signs and radiographic images are associated with a higher level of IgG4. Autoimmune pancreatitis is confirmed by biopsy. Treatment with prednisone often alleviates all the symptoms, as what happened in this case.