A regime for the postoperative ventilatory management of patients who have undergone operations under cardiopulmonary bypass is described and the problems discussed. It is recommended that the endotracheal tube be left in position for 24 hours, if this can be done without the use of unduly large amounts of analgesics, and mechanical ventilatory assistance is given by a patient-triggered ventilator. If further ventilatory assistance is required, the ventilator can be used with a facepiece. Should the patient's condition deteriorate, early tracheostomy is carried out. Continuous assisted ventilation through the tracheostomy tube will maintain the patient's condition and reduce the number of cases requiring full control of ventilation.