A case is described of a previously healthy obese woman in her fourth pregnancy who presented for caesarean section due to cephalopelvic disproportion (CPD). Forty minutes after a spinal anaesthetic a healthy child was delivered. Shortly after the injection of ergometrine and Syntocinon into the uterus, the patient described a general feeling of discomfort which was followed by convulsions and cardiac arrest. Resuscitation was successful and the circulation was restored. However, it was difficult to maintain oxygenation and the patient was mechanically ventilated for 24 hours and subsequently supplementary oxygen therapy was given for three days. A pulmonary scintigram on the fourth day after delivery showed large uptake defects indicative of pulmonary embolism. The patient recovered completely and was discharged home after two weeks. Differential diagnosis and measures to reduce the risk of deep vein thrombosis (DVT) are discussed.