This is the case of a para three, gravida three, who had a caesarean section for her first pregnancy and a normal delivery for the second one. During her third pregnancy the patient is hospitalised for first trimester bleeding. Ultrasounds show two liquid compartments separated by placenta. The lower one in cervico-isthmic position contains the foetus. During the 24th week gestation the pregnancy is complicated by severe metrorrhagia that leads to abdominal exploration and total hysterectomy. The pathology conclusions confirmed the per-operative impression of cervico-isthmic pregnancy. The authors emphasise the rarity of the cervico-isthmic pregnancy (1 for 10,000 pregnancies) and wonder about atypical evolution of this case and about the possibilities of saving the uterus by an earlier intervention in view of ultrasonographic data.