Objective: To investigate the preventive effects of rectal administration of indomethacin on pancreatitis and hyperamylasemia after endoscopic retrograde cholangiopancreatography (ERCP) in elderly patients with choledocholithiasis. Methods: 70 elderly patients with choledocholithiasis undergoing ERCP were randomly divided into indomethacin group (35 cases) and placebo group (35 cases). The patients in indomethacin group were given indomethacin through rectum 30 minutes before ERCP, the patients were given placebo through rectum. The serum amylase level of patients before ERCP, 3h and 24h after ERCP were detected; and to determine whether patients with pancreatitis and hyperamylasemia. Results: The serum amylase level of patients in indomethacin group 3h and 24h after ERCP were obviously lower than placebo group (P<0.05). The incidence rate of pancreatitis and hyperamylasemia after ERCP of patients in indomethacin group were respectively 5.71% (2/35) and 17.14% (9/35), which were all obviously lower than placebo group (P<0.05). Conclusions: Rectal administration of indomethacin before ERCP can remarkably reduce the incidence of pancreatitis and hyperamylasemia, so it is worth of clinical promotion.