A 31-year-old multiparous pregnant woman forced into labour with oxytocin, suffered a sudden circulatory collapse and, after the birth of her child, a defibrination syndrome with uterine haemorrhage. In the absence of a local cause, either placental or cervico-uterine, a diagnosis of amniotic fluid embolism was made. The time course was favourable, mainly thanks to the absence of acute pulmonary cardiogenic oedema and to the use of an anti-shock G suit. The authors point out the lack of actual in vivo paraclinical means for confirming the diagnosis.