Chorioangioma is a benign tumor ot aberrant vessels originated from the chorion. This is a case study of a 22 year-old woman presented at 22 weeks of her first gestation with polyhydramnios and a sonographic finding consistent with placental chorioangioma. The fetus developed hydrops two weeks later. After three more days the patient was admitted due to abdominal pain and vaginal bleeding. The membranes ruptured spontaneously. Five hours from admission she delivered spontaneously a dead 1450 grams male abortus. Uterine revision was performed due to incomplete placental expulsion. A solid mass was removed during the procedure. The mass was sent to pathology and was diagnosed as placental chorioangioma. Large chorioangioma require careful follow-up due to the possibility of rapid deterioration in fetal condition.