Background/Purpose: An increasing number of pediatric surgeons are using the laparoscopic approach to treat pyloric stenosis. The advantage of laparoscopic pyloromyotomy is uncertain and has not been evaluated in the setting of a pediatric surgery fellowship program. Methods: The authors retrospectively reviewed the medical records of all patients who underwent pyloromyotomy for congenital hypertrophic pyloric stenosis at their institution from January 1, 1997 through December 31, 2000 (n = 117). Information obtained included age, sex, weight, admission laboratory values, attending surgeon, resident surgeon and their level of training, operating time, intraoperative and postoperative complications, time to full feedings, incidence of postoperative emesis, duration of postoperative emesis, length of stay, and total hospital charges. These variables then were compared between the open (OPEN) and laparoscopic (LAP) groups. Results: From January 1, 1997 through December 31, 2000, 65 LAP and 52 OPEN pyloromyotomies were performed. Characteristics of patients in the OPEN and LAP groups were similar. The mean operating time was 33 ± 2 minutes for OPEN versus 38 ± 2 minutes for LAP (P =.07). The incidence of postoperative emesis (LAP, 68%, OPEN, 65%), duration of postoperative emesis (LAP, 7.3 ± 1.2 hours; OPEN, 8.1 ± 1.8 hours), and time to full feedings (LAP, 19.5 ± 1.6 hours; OPEN, 19.5 ± 1.3 hours) did not differ significantly between groups (P >.05). Mean postoperative length of stay in both groups was similar (LAP, 31 ± 5; OPEN, 28 ± 2 hours; P =.64). Mucosal perforation occurred in 5 patients (8%) in the Lap and 2 patients (4%) in the OPEN group (P =.39). Postoperative complications occurred in 12 LAP (18%) and 6 OPEN patients (12%, P =.31). Five LAP cases were converted to OPEN. In the LAP group there was one unrecognized mucosal perforation and one incomplete pyloromyotomy both of which required reoperation. As the laparoscopic approach was adopted, general surgery resident participation as operating surgeon in these cases decreased from 81% in 1997 to 19% in 2000. Hospital charges were higher in the LAP group, but not significantly (LAP, $6,676 ± 1,005; OPEN, $5,292 ± 306; P = 27). Conclusions: Laparoscopic pyloromyotomy has progressively become the dominant surgical approach to pyloromyotomy at our institution. The LAP and OPEN approaches have similar outcomes. However, the Lap approach may be associated with increased complication rates, a reduction in general surgery resident operative experience, and higher hospital charges. J Pediatr Surg 37:1068-1071. Copyright 2002, Elsevier Science (USA). All rights reserved.