An endodermal sinus tumor is a malignant germ cell tumor that usually arises in the gonads, but on rare occasion occurs in extragonadal locations. Our case was that of a 3 year old girl who complained of a rapid growing orbital mass. On histologic examination it revealed the typical picture of an endodermal sinus tumor and it also disclosed a positive reaction for alphafetoprotein using an immunoperoxidase technique. An orbital exenteration was performed followed by chemotheraphy, but the patient died 5 months after the onset of the disease.