Following antireflux surgery, children with persistent retching symptoms are presumably more likely to have delayed gastric emptying. We report 66 children between 2 weeks and 16 years of age who had an operation to control gastroesophageal reflux (GER). All patients had GER confirmed by 18- to 24-hour esophageal pH monitoring. Preoperative gastric emptying studies were performed in each patient with 99m-Tc sulfur colloid in apple juice. In addition to the percent gastric emptying (%GE), an effective gastric emptying was estimated by correcting the %GE for postcibal reflux (corrected %GE). Repeat 18- to 24-hour esophageal pH monitoring was performed postoperatively in all patients, and a repeat gastric emptying study was performed in 32 patients. After an average postoperative follow up of 6 months (range of 1 to 18 months), persistent retching was present in 12 (18%) patients. The retching was associated with dumping symptoms in six patients. Retching was seen in patients with a preoperative increase in effective gastric emptying (10/34, 29%, P less than .05) or a decrease in effective gastric emptying (2/15, 13%, NS), and not in patients with an effective gastric emptying within the control range (0/17, 0%). Postoperatively, retching with dumping symptoms was associated with an increased effective gastric emptying, and retching without dumping symptoms with a decreased effective gastric emptying. In conclusion, persistent retching followed anti-reflux surgery in children is related to extremes in effective gastric emptying. The preoperative measurement of corrected %GE identifies children at increased risk for this postoperative problem.