Nissen fundoplication gives lasting relief from symptoms of gastro-oesophageal reflux and cures endoscopic oesophagitis effectively. The histological effect on the oesophageal mucosa is less clear. We studied the long-term histological effect of Nissen fundoplication on refractory gastro-oesophageal disease with erosive oesophagitis or Barrett's metaplasia in 33 patients with biopsy both before and after antireflux surgery. The median postoperative interval to re-examination was 80 (range 37-110) months. Symptoms of reflux were greatly relieved; 31 (94%) of the 33 patients had none or, at the most, mild symptoms. Endoscopic oesophagitis was healed in 26 (79%) of the cases. The histological appearance of the oesophageal mucosa had been abnormal in all the patients preoperatively, but at follow-up it was normal in 22 cases (67%): in 89% of the patients without objectively observed recurrent reflux and in 45% of those with recurrence. Both the pre- and postoperative severity of the histological changes correlated significantly with the endoscopic grade of oesophagitis (r=0.42, P=0.017 and r=0.837, P=0.0001, respectively), but not with the clinical reflux score. In conclusion, Nissen fundoplication resulted in histological healing in the great majority of patients with oesophagitis.