PURPOSE: To evaluate the characteristic CT findings of neuroblastoma, we studied neurobalstomas. METHODS AND MATERIALS: We analysed CT findings of available 25 cases among pathologically proved 51 neurobalstomas from Jan. 1983 to Sept. 1990. RESULTS: The most frequent site of origin is adrenl gland (40%) and the second is retroperitoneum (32%) and the third ismediastinum (16%). Characteristic CT findings are as follows:Calcifications within the tumor is detected in 86% of abdominal neuroblastomas and 50% of mediastinal origin. Hemorrhagic and necrotic changes within the tumor is noted at 86% in the tumor of abdominal origin and 25% in mediastinal neuroblastomas. Contrast enhanced study showed frequently septated enhanced appearance with/without solid contrast enhancement. Encasements of major great vessels such as aorta and IVC with/without displacement by metastatic lymphnodes or tumor are frequently seen in 90% of abdominal neuroblastomas. Multiple lymphadenopathy are detected in 95% of abdominal neurobalstomas and 25% of mediastinal neuroblastomas. The most common organ of contiguous direct invasion is kidney in 6 cases and the next one is liver but intraspinal canal invasion is also noted in 2 cases. CONCLUSION: We concluded that diagnosis of neuroblastoma would be easily obtained in masses of pediatric group from recognition of above characteristic findings.