Background Obstructive jaundice is one of the commonest presentations that occurs that is seen by a surgeon. Extra hepatic biliary obstruction can occur at the level of the bile duct or because of external compression to the biliary tree. Carbohydrate antigen 19-9 it’s a high molecular weight carbohydrate rich glycoprotein that is seen in circulation often associated with mucin and has a half-life of approximately 14 hours. The carbohydrate antigen 19-9 is produced by the cells of the pancreatic pancreas and biliary ductal cells Even though there are several other investigations to confirm the diagnosis of malignancy like imaging, FNAC and biopsy, the tumor markers are probably the first tool that are used in order to see for the possible pathology when the reports of other investigations are awaited. As the levels of CA-19 are elevated in patients who have obstructive jaundice as shown by various studies we decided to evaluate its role in predicting the differentiation between benign and malignant pathologies and to see the pattern of alteration of carbohydrate antigen 99 in obstructive jaundice.