Teratomas and other germ cell tumors are common pediatric neoplasms. They may have gonadal and extragonadal locations. Congenital teratomas of the neck are unusual. Imaging provides early diagnosis, which is crucial for planning the delivery, definitive treatment and that of associated complications. This report describes the prenatal sonographic features of fetal neck teratoma and its role in early diagnosis and treatment. A 30-year-old gravid woman presented with polyhydramnios in 31 weeks. Ultrasound scan revealed fetal complex neck mass of heterogenous texture and marked polyhydramnios. The mass was excited in the early neonatal period and teratoma was confirmed on histology. (C) 2011 Egyptian Society of Radiology and Nuclear Medicine. Production and hosting by Elsevier B.V.