This chapter outlines the prenatal imaging and clinical diagnoses of neonatal and pediatric tumors. It discusses the antenatal natural history, and reviews available treatment options during the pre- and postnatal period for fetuses with prenatally diagnosed tumors. The differential diagnosis of a prenatally diagnosed intracranial tumor includes teratoma, which make up the majority of lesions, hemangioma and papilloma. Prenatal ultrasonography and fetal MRI are useful in evaluating and determining the etiology of the intracranial tumor. The surgical approach to bronchopulmonary sequestrations (BPS) is straightforward, with a muscle sparing thoracotomy or thoracoscopic approach for chest lesions and laparotomy or laparoscopy for subdiaphragmatic BPS, with particular attention to first controlling the anomalous blood supply in all cases. The most common primary hepatic tumor is hemangioma, followed by mesenchymal hamartoma, and hepatoblastoma. The differential diagnosis of mesoblastic nephroma includes hydronephrosis and multicystic dysplastic kidney, focal renal dysplasia, and diffuse nephroblastomatosis and nephroblastoma.