BACKGROUND Most children with Hirschsprung's disease (HD) can be treated with a transanal endorectal pull-through (TEP) procedure. The authors have developed a simple technique of submucosal pressure-air insufflation (SI) to facilitate the submucosal dissection, which is one of the crucial parts of the operation. METHODS Six patients with HD were treated by using TEP in one year. After adequate positioning and exposure, anal mucosa was incised 1 cm above the dentate line, and 4-quadrant SI with a simple system of scalp-vein needle connected to a 20-mL syringe was used in all of the patients. Submucosal proctectomy, aganglionic and dilated segment colectomy, and coloanal anastomosis were completed transanally, but, in 2 of the patients, laparoscopic assistance to release the colon was required. RESULTS There were no intraoperative and postoperative complications related to SI. Submucosal dissections were completed smoothly in all of the patients with negligible amount of bleeding. The only complication during the submucosal dissection was mucosal perforation at the site of previous rectal biopsy in 2 patients. Average operating time was 2.7 hours (range, 90-180 min), and mean length of resected bowel was 22.5 cm (range, 12 to 42 cm). Follow-up is 8 to 14 months. Frequent bowel movements (>8 times per day) and perianal dermatitis were observed in 2 patients but returned to acceptable limits in 3 months. One patient had to undergo reoperation for adhesive intestinal obstruction. CONCLUSIONS SI is simple, and offers a safe and faster dissection with minimum amount of bleeding during the endorectal mucosectomy in TEP procedure.