The purpose of this study was to investigate the severity of presenting symptomatology in patients with unilateral choanal atresia and to assess the surgical results of patients undergoing transnasal endoscopic repair. A retrospective review of all patients with choanal atresia presenting to the author between 1990 and 1997 was performed, identifying 13 patients with unilateral choanal atresia. These patients were analyzed with respect to presenting symptomatology, preoperative computed tomography scans, appearance, type of surgical repair, and surgical results for patients undergoing endoscopic transnasal repair. Eleven patients underwent successful endoscopic transnasal repair, one patient underwent conversion to transpalatal repair after an unsuccessful attempt at transnasal endoscopic repair and one patient underwent a planned transpalatal repair. Eleven patients who underwent repair by transnasal endoscopic technique have all done well with follow-up ranging from 3 months to 7 years. Although the symptomatology of unilateral choanal atresia is not as dramatic as bilateral choanal atresia, significant airway symptomatology may be present, especially in children presenting at a very young age. It appears that transnasal repair of unilateral choanal atresia is an excellent treatment modality with excellent postoperative surgical results.