Pulmonary embolism occurring during pregnancy is a rare accident but that still brings about a high mother mortality; it seems to be five to six times more frequent during the pregnancy and the post-partum than for non-parturient women who don't take any estro-progestogens, pulmonary embolism would involve complications for 0.5/1000 pregnancies before delivery. As it presents a lot of diagnostic problems, it is under-estimated. The vascular radiological examinations expose the foetus or embryo to considerable radiation and to a risk of foetal hypothyroidism leading to backwardness. The lung perfusion scanning has the advantage of not injecting iodine but is not specific. Fortunately, some medical examinations such as plethysmography or Doppler echography are safe and can also guide the clinician. As far as therapy is concerned, intravenous heparin is the first intention treatment, it can be replaced subsequently by subcutaneous heparin (low molecular weight heparin). In case of heavy pulmonary embolism endangering the vital prognosis of the patient, in case of clinical or biological resistance to the medical treatment, it could be necessary to perform a pulmonary embolectomy with, if necessary, vena cava interruption with insertion of a mechanical filter.