Background & Aims: Endoscopic retrograde cholangiopancreatography is commonly performed to remove bile duct stones. The aim of this study was to determine short-term outcomes of endoscopic balloon dilation of the sphincter of Oddi compared with sphincterotomy for stone extraction. Methods: A randomized, controlled multicenter study of 117 patients assigned to dilation and 120 to sphincterotomy was performed in a spectrum of clinical and academic practices. Results: Characteristics of the patients, procedures, and endoscopists were similar except that dilation patients were younger. Procedures were successful in 97.4% and 92.5% of the dilation and sphincterotomy patients, respectively. Overall morbidity occurred in 17.9% and 3.3% (P <. 001; difference, 14.6; 95% confidence interval, 7-22.3) and severe morbidity, including 2 deaths, in 6.8% and 0%(P <. 004; difference, 6.8; 95% confidence interval, 2.3-11.4) for dilation and sphincterotomy, respectively. Complications for dilation and sphincterotomy, respectively, included: pancreatitis, 15.4% and. 8% (P <. 001; difference, 14.6; 95% confidence interval, 7.8-21.3); cystic duct fistula, 1.7% and 0%; cholangitis,. 9% and. 8%; perforation, 0% and. 8%; and cholecystitis, 0% and. 8%. There were 2 deaths (1.7%) due to pancreatitis following dilation and none with sphincterotomy. The study was terminated at the first interim analysis. Dilation patients required significantly more invasive procedures, longer hospital stays, and longer time off from normal activities. Conclusions: In a broad spectrum of patients and practices, endoscopic balloon dilation compared with sphincterotomy for biliary stone extraction is associated with increased short-term morbidity rates and death due to pancreatitis. Balloon dilation of the sphincter of Oddi for stone extraction should be avoided in routine practice.