Neuroblastoma is the most frequent extracranial solid tumor in childhood, but it is seldom diagnosed prenatally. We report a case of adrenal neuroblastoma identified at 39 weeks' menstrual age and successfully treated by postnatal surgery and chemotherapy. Sonography revealed a hyperechoic mass in the right upper quadrant of the fetal abdomen associated with hydramnios and hydronephrosis. Two days after delivery, the tumor was resected. No metastasis was identified. The infant received 6 cycles of chemotherapy, and at 2 years of age she was well, with no signs of recurrence.