A study of the haemodynamic effects of an injection of 0.3 mg/kg of Etomidate was carried out in 11 multiple trauma patients under constant controlled ventilation. At the 3 rd minute after injection there was a slight, but significant, increase in cardiac output and in the systolic index of the left ventricle, persisting at the 20th minute. It may be concluded that the injection of a dose of 0.3 mg/kg has no harmful haemodynamic effects in this type of patient.