This study was aimed at evaluating haemodynamic changes during an anaesthetic sequence for full stomach, using propofol as induction agent and volatile anaesthetics for maintenance of anaesthesia in infants scheduled for surgical cure of hypertrophic pyloric stenosis. After correction of preoperative blood electrolyte and metabolic disturbances with appropriate i.v. hydrating solutions, anaesthesia was induced with propofol and suxamethonium. Infants were divided in two groups according to the volatile anaesthetic agent used for maintenance of anaesthesia after tracheal intubation: halothane (n = 16) or isoflurane (n = 15). The two groups were identical regarding weight (4.28 +/- 0.6 vs 4.14 +/- 0.76 kg), age (1.6 +/- 0.9 vs 1.5 +/- 0.6 months), preinduction heart rate (155 +/- 22 vs 151 +/- 22 b min(-1)) and systolic-diastolic arterial pressure (96 +/- 18/58 +/- 12 vs 105 +/- 16/67 +/- 15 mmHg). Propofol and suxamethonium doses were identical, 3.9 +/- 1 mg kg(-1) and 1.3 +/- 0.6 mg kg(-1) respectively in halothane groupe, vs 4.3 +/- 0.8 mg kg(-1) and 1.3 +/- 0.4 mg kg(-1) in isoflurane group. Heart rate did not change after induction of anaesthesia, while arterial blood pressure decreased significantly (p < 0.001). However, blood pressure remained within the normal range for age throughout the procedure. Mean duration of surgery was shorter in halothane group (64 +/- 16 vs 79 +/- 17 min, p < 0.05), however time-interval from the end of surgery to tracheal extubation (12 +/- 6 vs 15 +/- 8 min) was short and identical in the two groups. It is concluded that propofol seems to be appropriate for infants requiring a rapid i.v. sequence induction for ''full-stomach'', as haemodynamic changes remain minimal.