Laparoscopic and thoracoscopic techniques have provided a new dimension in the correction of functional disorders of the esophagus. Therapeutic success, however, depends on the confirmation of esophageal disease as a cause of the symptoms, on understanding the basic cause of dysfunction and on identifying the surgical patient. This study is a retrospective study of patients submitted to surgery using the Lind procedure for gastroesophageal reflux disease (GERD). The purpose of this study is to establish the value of the routine use of esophageal manometry and 24-hour pH monitoring in order to select patients and perform pre and postoperative functional evaluation. Forty-one patients (68.3%) had a hypotonic lower esophageal sphincter. The average pressure was 9.2 mm Hg preoperatively and 15.2 mm Hg postoperatively, with an increase of 6.0 mm Hg. This increase was 8.8 mm Hg in hypotonics and 4.3 mm Hg in the normotonics. There was a certain degree of hypomotility of the esophageal body in 14 patients (23.3%) and, of this group, 4 (28.5%) improved postoperatively. Pathological acid reflux was found in 51 cases (85.0%) by pH monitoring. The mean of the preoperative DeMeester score was 31.4, later dropping to 3.2. Esophageal manometry and 24-hour pH monitoring are effective methods for revealing the level of functional modification established by anti-reflux surgery and for helping to objectively perform the selection.