In order to compare the standard Nissen fundoplication with the more recent Angelchik antireflux prosthesis, 47 pediatric-sized, developmentally disabled patients were prospectively randomized to receive either of these gastroesophageal antireflux procedures. The two groups were comparable at the time of surgery with regard to age, weight, surface area, emesis, number of chest radiographs, medications, lower esophageal sphincter pressure, and number and duration of reflux episodes during standard acid reflux testing. The Angelchik group required significantly less anesthesia time than the Nissen group: 107.4 +/- 22.6 min (mean +/- SD) versus 156.5 +/- 42.4 min (p less than 0.001). There was no difference in length of postsurgical hospital stay. Six months after surgery, both groups showed improvement. There was no significant difference between the Angelchik and Nissen groups in mean subjective assessment score, increased weight gain, decreases in emesis, numbers of chest radiographs, hospital days, or medications, increased lower esophageal sphincter pressure, or decreased numbers and duration of reflux during acid reflux testing. Long-term follow-up of eight Angelchik and 10 Nissen patients 12-30 months postsurgery (Angelchik 21.6 +/- 6.0 months, Nissen 21.9 +/- 5.0 months) demonstrated no significant difference in the percent of time the distal esophageal pH was below 4.0. Significant complications potentially related to the type of procedure developed in 1/21 patients in the Angelchik group and 1/17 patients in the Nissen group. We conclude that both procedures are usually effective for the surgical treatment of gastroesophageal reflux. Further study is indicated in order to establish the long-term superiority of one procedure.