Acute postoperative pancreatitis can occur after any major operative procedure. The problem has been shown to develop more frequently after abdominal operations and to have the greatest likelihood of occurring after biliary tract operations. Various factors associated with biliary tract disease and the operation that increase the frequency of APP have been identified. An important association exists between preoperative pancreatitis or elevated pancreatic enzyme levels and the development or exacerbation of APP. Choledocholithiasis and operations or endoscopic procedures that manipulate the common duct sphincter increase the frequency of APP. Acute calculus gallbladder disease is associated with an increased frequency of APP after cholecystectomy. The study by the Swiss Association of Laparoscopic and Thoracoscopic Surgery has generally demonstrated that these previously defined relationships still exist in the era of endoscopic management of choledocholithiasis and LC. Acute postoperative pancreatitis developed after LC in patients with previous pancreatitis, choledocholithiasis, ERCP, and acute cholecystitis.