One hundred consecutive patients had a primary Nissen fundoplication for gastroesophageal reflux disease. None of the patients had previous gastric or esophageal surgery or evidence of esophageal stricture or motility disorder. The primary symptom was persistent heartburn in 89 patients and aspiration in 11. An abnormal pattern of esophageal acid exposure was documented in all patients with 24-hour esophageal pH monitoring. By actuarial analysis, the operation was 91% effective in the control of reflux symptoms over a 10-year period. The incidence of postoperative symptomatic gas bloat and increased flatus was lower in patients with preoperative abnormal manometric measurements of the distal esophageal sphincter (p less than 0.05). Three modifications in operative technique were made during the course of the study to minimize the side effects of the operation. First, enlarging the caliber of the bougie to size the fundoplication reduced the incidence of temporary swallowing discomfort from 83 to 39% (p less than 0.01). Second, shortening the length of the fundoplication decreased the incidence of persistent dysphagia from 21 to 3% (p less than 0.01). Third, mobilizing the gastric fundus for construction of the fundoplication increased the incidence of complete distal esophageal sphincter relaxation on swallowing from 31 to 71% (p less than 0.05). This was done to prevent the delayed esophageal acid clearance secondary to incomplete sphincter relaxation observed after operation in five of 36 studied patients. It is concluded that by proper patient selection and the incorporation of the above surgical techniques, the Nissen fundoplication can re-establish a competent cardia and provide relief of reflux symptoms with minimal side effects.