Diagnosis and management of autoimmune pancreatitis during pregnancy. Autoimmune pancreatitis is a rare and life-threatening condition with increased maternal and fetal mor- bidity and mortality. Autoimmune pancreatitis may result in a mass-forming lesion in the pancreas resembling pancreatic cancer; therefore, meticulous and careful investigations must be done to avoid misdiagnosing autoimmune pancreatitis as pancreatic cancer. Since autoimmune pancreatitis improves dramatically to steroid therapy, accurate diagnosis of autoimmune pancreatitis can avoid unnecessary procedures, surgeries, and pancreatic re- section. A case of a pregnant lady in her third trimester was presented with abdominal pain, nausea, and vomiting. On examination, there was tenderness in both epigastric and right hypochondrium associated with elevated serum amylase, liver transaminases, alka- line phosphatase, gamma-glutamyl transpeptidase, and immunoglobulin G4. Both abdom- inal ultrasound and magnetic resonance cholangiopancreatography showed a pancreatic head lesion with dilation in both pancreatic duct and common bile duct. Steroid was initi- ated that resulted in rapid and dramatic responsiveness. Acute pancreatitis is uncommon during pregnancy, and autoimmune pancreatitis is a very rare form of acute pancreatitis; therefore, a clear and rapid assessment, diagnosis, and management plan are necessary to avoid maternal and fetal morbidity and mortality.