INTRODUCTIONERCP is widely performed for the diagnosis and management of various pancreaticobiliary diseases. Early complications after ERCP include acute pancreatitis, bleeding, perforation, and infection (cholangitis and cholecystitis) Of these ERCP related complications, pancreatitis remain the most common with a reported incidence of 2 to 15% in multicenter prospective studies.1-5 Most cases of post ERCP pancreatitis are mild, showing complete recovery in a few days. After severe ERCP related Pancreatitis however., secondary consequences (e.g. pancreatic pseudocyst and abscess) and multiorgan failure frequently develop: surgical intervention and prolonged hospital stay are usually required, and eventually the patient dies. In a reported series of 7,869 patients undergoing diagnostic or therapeutic ERCP, 3 patients (0.04%) died from severe post-ERCP Pancreatitis. The prevention of post ERCP pancreatitis has been a never-ending challenge ever since ERCP was introduced in clinical settings in the 1970s. The exact pathogenesis of post-ERCP pancreatitis has remained unclear but diverse factors, which include mechanical injury, hydrostatic injury, chemical and allergic injury. enzymatic Injury, infection and thermal injury have been postulated as causes of post ERCP pancreatitis.6-8 Many pharmacologic agents of different types he been used to prevent post ERCP pancreatitis on the assumption that they Pharmacologically inhibit one or more of the aforementioned factors associated with pancreatic damage. Irrespective of the etiology of acute pancreatitis, the activation of proteases enzymes starting with trypsinogen activation to trypsin in pancreatic acinar cells, has been considered to play an Initial role in the ABSTRACT Background: Pancreatitis remains the major complication of endoscopic retrograde cholangiopancreatography (ERCP), and hyperenzymemia after ERCP is common. Ulinastatin, a protease inhibitor, has proved effective in the treatment of acute pancreatitis. The aim of this study was to assess the efficacy of ulinastatin, compare to placebo study to assess the incidence of complication due to ERCPP procedure. Methods: In this study a randomized placebo controlled trial, patients undergoing the first ERCP was randomizing to receive ulinastatin one lakh units (or) placebo by intravenous infusion one hour before ERCP for ten minutes duration. Clinical evaluation, serum amylase, ware analysed before the procedure 4 hours and 24 hours after the procedure. Results: Total of 46 patients were enrolled (23 in ulinastatin and 23 in placebo group). The incidence of Hyper enzymemia is lower in ulinastatin group (13 %) than in placebo group (30.4%). Conclusions: Prophylactic short-term administration of ulinastatin one lakh units intravenously, one hour before ERCP procedure is effective when compared to placebo infusion.