A 32 year old woman, at the 23rd week + 3 days gestational age, was admitted to our institute for a therapeutic abortion decided because of an ultrasonographic diagnosis of anencephaly. This woman had already had a cesarean section caused by acute fetal stress during labor in 1992. We decided for a labor induction with prostaglandin analogues: we used gemeprost vaginal tablets and after injectable sulproste. During this treatment we observed increasing abdominal pain, slight genital haemorrhage, vanishing HFR, an elevated reduction of haemoglobin (7 g): so, we thought of a uterine rupture. During the intervention, we observed a conspicuous haemoperitonei caused by a complete yielding of the old hysterotomic suture at the cervix border; the placenta and its adnexals get out from the uterine breach and the fetus fluctuated in the abdominal cavity, also enclosed in his unruptured amniotic fluid. Post-intervention course was satisfactory and we discharged the patient during the 7th admission day. Our personal experience shows the importance of a careful monitoring of maternal and fetal conditions during labor induction, particularly in those cases in which a woman was already submitted to a hysterotomy, and especially when the use of different types of prostaglandin drugs may be necessary.