We have presented a case of luteoma of pregnancy, an uncommon ovarian lesion that is usually detected incidentally during cesarean section or postpartum tubal ligation. It is felt to be nonneoplastic, is hormonally stimulated, and regresses after childbirth. It is important to distinguish it from neoplastic lesions of the ovary that can occur in the same population, particularly steroid cell tumors, although this can be a difficult differential diagnosis.