Antireflux surgery is supposed to prevent the development of adenocarcinoma in patients with Barrett's esophagus. The purpose of this study was to determine the prevalence of adenocarcinoma late after antireflux surgery. A total of 161 patients with long-segment Barrett's esophagus had antireflux surgery and were followed for a mean of 148 months (range 54 to 268 months) Clinical, endoscopic, histologic, and functional studies were performed. Of the original 161 patients, 147(91.3%) completed long-term follow-up. Six patients (4.1%) developed adenocarcinoma 4,5,6,9,17, and 18 years, respectively, after surgery. Five were men. Two of them were asymptomatic for 12 and 17 years. Three of them had extra-long-segment Barrett's esophagus. Five underwent manometric evaluation with only one showing an incompetent lower esophageal sphincter. In two cases, 24-hour pH studies showed massive acid reflux. Two patients had early adenocarcinoma, whereas four had advanced carcinoma. Adenocarcinoma in long-segment Barrett's esophagus seems to develop mainly in patients with recurrence of pathologic reflux, especially among men. A review of the English language literature during the last 23 years found 25 articles dealing with Barrett's esophagus and antireflux surgery. Most of these reports had only a few patients with short-term follow-up (<60 months). To determine the true prevalence of this complication, a long-term objective follow-up is necessary.