Fetus in fetu is a rare condition in which a monozygotic, monoamniotic, dichorionic twin is included within the body of its sibling [19]. In 1956, Lord presented the first systematic review of the subject, comprising 11 case reports including 1 of her own. She found that many of the earlier reports dealt with teratomas and not true fetus in fetu. In 1958, Willis defined fetus in fetu as a benign mass with a vertebral column, as identified by radiography or at dissection, with other bones and organs arranged around the axis. This is to be differentiated from a true teratoma, which shows no axial arrangements and has definite malignant potential [26]. This paper presents a case occurring in a newborn male and a review of the literature since Lord's initial review.