Summary. A series of 50 patients was studied by esophageal manometry and X-ray prior to fundoplication and for a three month thereafter. In 49 patients a functionally intact gastroesophageal junction was documented; in one patient disintegration of the plication occured. The resting pressure of the lower esophageal sphincter was found preoperatively in the range of 10,4 + 3,7 mrs Hg; postoperative values increased to 19,0 +_ 6,9 mm Hg. 10% of patients complained postoperatively of temporary dysphagia. Only in a single instance continued dysphagia had to be treated. Inadvertently two patients were vagotomized during the operation. The data are discussed in relevance to the technical details of the operative procedure.