We conducted a retrospective case-series review to identify the various diagnoses of neoplasms of the nasal cavity and paranasal sinuses in a pediatric population. Our study group was made up of 54 children-23 boys and 31 girls, aged 8 months to 16 years (mean: 9 yr). All patients had been diagnosed with a tumor of the nasal cavity or paranasal sinuses between Jan. 1, 1955, and Dec. 31, 1999, at one of four university-based, tertiary care referral centers. We compiled data on tumoral characteristics (location, size, and histopathology), morbidity and mortality, and rates of recurrence. Lesions included adnexal neoplasm, ameloblastic fibro-odontoma, basal cell carcinoma, benign fibrous histiocytoma, blue nevus, chondrosarcoma, compound nevus, epithelioma adenoides cysticum, esthesioneuroblastoma, Ewing sarcoma, fibrosarcoma, giant cell granuloma, granulocytic sarcoma, hemangioma, hemangiopericytoma, Langerhans cell histiocytosis, lymphangioma, lymphoma, melanoma, neuroblastoma, neurofibroma, ossifying osteofibroma, osteochondroma, osteosarcoma, port wine stain, rhabdomyosarcoma, Spitz nevus, and xanthogranuloma. To the best of our knowledge, this is the largest such study of its kind to date. We believe that the large size of this study and the data on disease incidence will allow clinicians to be better informed of the differential diagnosis of neoplasms of the nasal cavity and paranasal sinuses in the pediatric population.