We describe the case of a 9-day-old female referred for a left posterior mediastinal mass, which we diagnosed as a thoracic neuroblastoma (TNBL) by biopsy. We present this case report to illustrate the classic radiographic, CT, MRI, and nuclear-medicine features of the disease. We believe it is an informative teaching resource for trainees and radiologists. TNBL is a solid childhood tumor of neuroblast origin, which presents in children most often in the first years of life. Treatment of TNBL is largely directed by staging and the criteria for staging rely heavily on multimodal imaging-especially MRI and I-123 metaiodobenzylguanidine (MIBG) bone scan.