Background: Various techniques have been used for laparoscopic gastric bypass. This Study was performed to survey American Society for Bariatric Surgery practicing surgeons on how they perform laparoscopic gastric bypass. Methods: An Internet-based survey was sent to all practicing surgeons in the American Society for Bariatric Surgery database by way of e-mail. The survey was divided into sections. including experience, Pouch, limbs, gastrojejunostomy (GJ). jejunojejunostomy, and band. The survey results were collected from the Internet site after 4 months. Results: A total of 215 surgeons responded; 98% stated they performed laparoscopic gastric bypass. The surgeons had performed an average of 423 cases in their career and 95 cases during the past 12 months. The average pouch size was 25 cm(3) and approximately one half of the surgeons (49%) measured the pouch size by the distance for the gastroesophageal junction. Almost all Surgeons (99.5%) performed Roux-en-Y and not loop GJ. The average biliopancreatic limb length was 48 cm, and the average Roux limb was 114 cm. About one half of the surgeons (46%) measured the limb length with an open grasper, and few (7%) used a suture or umbilical tape. The antecolic and antegastric approaches were the more common. The percentage of those using the circular stapler, linear stapler, and hand sewing was 43%, 41%, and 21% for the GJ technique. Most Surgeons (93%) routinely tested the GJ intraoperatively. The percentage of those using staple anastomosis and hand-sewn common enterotomy, double stapling. triple stapling. and hand sewing was 53%, 36% 13%, and 1% for the jejunojejunostomy technique. Most Surgeons (94%) closed at least one mesenteric defect. Also, most surgeons (95%) did not place a band around the Pouch. Conclusion: Technical variations exist in how laparoscopic gastric bypass procedures are performed by American Society for Bariatric Surgery practicing surgeons. Additional research is needed to explore the links between the technical variations and outcomes. (Surg Obes Relat Dis 2008;4:166-173.) (C) 2008 American Society for Metabolic and Bariatric Surgery. All rights reserved.