Objective: To evaluate the efficacy of topical mitomycin in providing the patency of the neochoanae in children undergoing transnasal endoscopic congenital choanal atresia (CA) repair. Methods: A retrospective analysis of surgical results in CA patients who were treated in Selcuk University, Meram Medical Faculty, Department of Otolaryngology between November 2002 and November 2009 was performed. All patients underwent transnasal endoscopic approach using nasal telescopes and traditional sinus instrumentation together with a microdebrider. Mitomycin was used according to the senior surgeon's preference, and certainly not in a randomized fashion. After completion of surgery, mitomycin 0.4. mg/ml was applied to the neochoanae for 3. min. Postoperative stenting was performed in all patients. Results: CA was unilateral in 8 subjects (mean age 71.8. ±. 41.7 months; range 18 months-144 months) and bilateral in 12 subjects (mean age 4.6. ±. 1.3 days; range 3-7 days). Among the subjects, 75% was female in both groups. Fourteen subjects under endoscopic repair without mitomycin, whereas mitomycin was used in 6 patients (4 bilateral, 2 unilateral). Stents were left at least 3 weeks postoperatively (mean 31. ±. 10 days; range 21-45 days). The patients were followed-up at least 6 months (range 6-72 months). No symptomatic restenosis requiring further dilatations was seen in patients treated with preoperative mitomycin, whereas restenosis was detected in 6 subjects (42.9%) treated without mitomycin postoperatively within 6 months period (Fisher's Exact Test 2-sided, p=. 0.12). These subjects underwent revision endoscopic repair with mitomycin and had no need for further dilatations with acceptable control of symptoms during a follow-up period ranging between 14 and 78 months. Conclusion: Mitomycin improves the surgical treatment outcome of CA and reduces the rate of restenosis significantly without any complications. However, further prospective randomized studies are needed to fully investigate the benefits of mitomycin therapy in CA surgery. © 2010 Elsevier Ireland Ltd.