A case of teratoma from the placenta is described. Sixteen previous reports of this entity are briefly reviewed, and the histological features, differential diagnosis and pathogenesis of the placental teratoma are discussed. Authors consider the placental teratoma a true tumor and not a fetus amorphus. Placental teratomas are extremely rare tumors. Sixteen cases have been reported since first described by Morville in 1925. Placental teratoma has not been reported in China.