Oral losartan given in the dose of 50 mg one hour before ERCP was studied in the prevention of post ERCP pancreatitis in 50 patients indicated for ERCP in comparison with another 50 patients underwent ERCP without receiving oral losartan.

Inclusion Criteria:

• Any adult patient indicated for ERCP
• Patients with obstructive jaundice.
• Patients with dilated intra-hepatic or extra-hepatic bile ducts due to malignant or benign lesions.

Exclusion Criteria:

• Patients refusing to undergo the procedure or signing the informed consent
• Patients with clinically evident acute pancreatitis before the procedure
• Patients with previous endoscopic or surgical sphincterotomy
• Patients with current use of losartan
• Patients who are allergic or hypersensitive to losartan or hydro soluble contrast solutions
• Patients receiving NSAIDS within a week prior to assessment
• Patients with severe co-morbid conditions as cardiovascular disease, renal failure or decompensated liver cirrhosis.