Intravenously administered salbutamol inhibited premature labour for at least 48 hours in 49 of 76 patients (64%), but was more effective (89%) when the cervical dilatation was less than 2 cm, and no apparent cause for the premature labour was evident. Even when premature labour complicated multiple pregnancy, hydramnios, or followed a small antepartum haemorrhage, suppression of labour could often be achieved for at least 48 hours, thus following the administration of betamethasone or the transfer of the patient to a hospital with intensive care facilities for both mother and child. Treatment with betamethasone, in addition to salbutamol, was associated with a less severe form of respiratory distress syndrome, and did not increase the risk of maternal or fetal infection, except in patients with cervical incompetence when 46.2% of such patients were infected.