The teratoma is a congenital neoplasm which contains multiple tissues representative of more than one germinal layer, and which exhibits a pattern of growth foreign to its anatomic site. The structure shows a benign, but varied, cytology, and ranges from a tumor containing tissues derived only from two germinal layers to a partially formed fetus. Such growths are apparently rare in the orbit since there are cnly about 30 case reports in the world literature. The growth of the tumor is rapid and locally aggressive, and usually necessitates exenteration of the orbit within the neonatal period. The subject of teratomata of the orbit has been recently reviewed by Hoyt and Joe,1 and has been elucidated with customary precision in the new textbook by Duke-Elder.2 Case Report A 6-week-old girl was referred by Dr. Charles Grant to Dr. Algernon B. Reese with a progressive left exophthalmos present since birth.