BACKGROUND Effective surgical treatments for achalasia of the esophagus facilitate swallowing by division of muscles that fail to relax normally during swallowing. If esophagocardiomyotomy is performed, a complementary antireflux procedure is mandatory to prevent postoperative gastroesophageal reflux. We evaluated patients who had undergone a circumferential antireflux procedure after esophagocardiomyotomy to determine the effects of this procedure in patients with an aperistaltic esophagus. METHODS During the past 15 years we treated 94 patients with achalasia by use of pneumatic dilation (66), esophageal myotomy (19), or esophagocardiomyotomy with floppy Nissen fundoplication (24). Achalasia was defined by radiographic and manometric criteria until 1986 when computerized axial manometry of the esophagus was initiated, providing information about the three-dimensional contour and "volume" of the lower esophageal sphincter in addition to the usual manometric data. RESULTS Dysphagia was effectively relieved in all, and neither postoperative reflux nor esophageal obstruction was observed after esophagocardiomyotomy followed by floppy Nissen fundoplication. The measured lower esophageal sphincter pressures and sphincter volume were markedly reduced. CONCLUSIONS Esophagocardiomyotomy with floppy Nissen fundoplication is an effective treatment for achalasia; clinical evidence of obstruction of the esophagus was not seen, and manometric data were typical of a weakened sphincter.