We performed a prospective, randomized study comparing the efficacy and safety of the combination of remifentanil and the newer volatile anaesthetics desflurane and sevoflurane with a conventional anaesthetic technique using alfentanil and desflurane. Forty five ASA class I or II female patients were randomly assigned to one of three groups. Following induction with propofol patients received a continuous infusion of remifentanil in combination with either 0.5 MAC desflurane (n = 15) or sevoflurane (n = 15), a third group (n = 15) received 1 MAC of desflurane with bolus doses of alfentanil for maintenance of anaesthesia. Remifentanil infusion and alfentanil (bolus) were titrated to responses to surgical stimuli while the concentration of volatile agents was kept unchanged. The number of responses to surgical stimuli was similar in the two remifentanil groups and higher in the alfentanil-desflurane group. Recovery times were similar in all groups. The incidence of postoperative side effects was high in the three groups. No awareness occurred and patient satisfaction in the two remifentanil groups was comparable to the conventional anaesthetic technique.