During a 3-year period, nine girls and two boys (age range, 2 days-13 years) with congenital choanal atresia were evaluated by computed tomography (CT). Other associated congenital anomalies, primarily craniofacial anomalies, were present in six of the 11 patients. In six patients the atresia was bilateral and consisted of both bony and membranous components. Of the five patients with unilateral atresia, the lesions were on the right in three and on the left in two. CT demonstrated the atresia, choanal stenosis, septal deviation, and thickening of the vomer and palatine bone. The ease of CT examination and the high accuracy of the results make it the preferred imaging method for evaluating choanal atresia.