We report a partial fetus-like structure (homunculus) in benign ovarian mature cystic teratoma removed from a 23-yr-old female. The cyst displayed various tissues derived from the three germ layers. The homunculus had a distinguished fetal cranial structure with one upper extremity. A partially developed osteocartilagenous skeleton was identified in the cranial structure of the homunculus. Intracranial structures such as cerebral cortex, retinal pigment, and leptomeninges were extruded from the partially disrupted calvarium.