Large-caliber prostheses, 11.5-12 French, were placed in 167 patients (183 attempts, 91% success) presenting with obstructive jaundice. Thirty-three patients had additional prostheses placed to selectively decompress intrahepatic ducts obstructed by cholangiocarcinoma. In this prospective unrandomized series, there were 43 lesions of the common hepatic duct, 123 of the common bile duct (96 pancreas, 27 cholangiocarcinoma) and 17 ampullary. Transient fever responding to parenteral antibiotics occurred in 11 patients who did not receive prophylaxis, whereas only 2 patients who received antibiotics prior to the procedure developed fever subsequently. Four patients bled subsequent to sphincterotomy, 1 requiring a 2-unit transfusion. Pancreatitis occurred in only 1 patient. The mean hospital stay was only 3 days, range 1-10 days, with most patients being discharged within 48 hours. No procedural deaths occurred. The patency rate of this new, larger 12 Fr. prosthesis is significantly longer than that for the 10 Fr. stent, 190 days for 12 Fr., 150 days for 10 Fr. Given the advantages of the larger prosthesis, i. e., increased patency and function and decreased rehospitalization rate, the authors recommend this method of palliation for obstructive jaundice.