Abstract: The present invention relates to a prosthetic anti-reflux valve for treating gastroesophageal reflux disease (GERD) and methods for its use. The preferred methods described provide for transoral insertion of a prosthetic anti-reflux valve and its fixation within the stomach interior. One advantage of such preferred embodiment of the present invention over prior devices is the elimination of the need for fixation of a prosthetic device within the esophagus, thus permitting a more natural and less obstructed, and even unobstructed, function of the esophagus.