The objective of this study was to review the characteristics of congenital nasal pyriform aperture stenosis (CNPAS) in a series of 20 children seen between 1993 and 1996. The diagnosis was made by physical examination and computed tomography scan. A single central maxillary incisor was detected in 12 cases (60%). Three children had morphological abnormalities of the pituitary gland shown on magnetic resonance imaging. One child had an antidiuretic hormone deficiency, and another child had a growth hormone deficiency. Two children had craniosynostoses, 1 of which was Apert's syndrome. All patients underwent operation by a sublabial approach, and 1 was referred for a columellar necrosis after nasal stenting. After surgery, all patients showed improvement, and the nasal stenting was usually removed 1 week after surgery. Follow-up revealed normal breathing. In conclusion, CNPAS was previously considered to be an unusual cause of nasal obstruction in neonates and infants. The number of cases treated recently in our department suggests that this newly recognized entity is more common than expected.