Although surgery within the lumen of the gut has been performed for many years, this has traditionally involved a laparotomy and enterotomy. With the advances in flexible endoscopy, surgeons and gastroenterologists have been able to perform therapeutic procedures with instruments introduced through the working channel of flexible endoscopes. These procedures, however, have been mainly limited to technically minor ones, such as injection and cautery of bleeding ulcers and resection of polyps and small mucosal lesion. More recently, laparoscopic surgeons have been able to isolate the lumen of hollow organs as a separate working space and develop instrumentation and technique specifically for intraluminal surgery. This paper provides an overview of our approach, which includes development of a new device for intraluminal access and operations within the lumen of the stomach. Future application of this approach will also be discussed.