This study examined the intra-operative and postoperative characteristics of a remifentanil infusion alone, or intermittent fentanyl bolus admistration combined with a propofol infusion, for the anaesthetic management of patients undergoing shock wave lithotripsy. One of the key parameters investigated was the time to discharge. Fifty patients scheduled for extracorporeal shock wavelithotripsy (ESWL) were randomly allocated to receive either a continuous infusion of 0.2-0.4 micro g.kg-1.min-1 of remifentanil (Group 1) or a bolus of 3 micro g.kg-1 fentanyl followed by a continuous infusion of propofol at a rate of 2 mg.kg-1.h-1 with additional boluses of 0.05 mg fentanyl administered as required (Group 2). Both anaesthetic techniques were found to provide satisfactory analgesia and intra-operative conditions for ESWL. However, patients in the remifentanil Group 1 showed a higher incidence of nausea (52% vs. 0%, p < 0.01) and retching (36% vs. 0%, p < 0.01) 120 min following ESWL compared to Group 2. This resulted in prolonged discharge times (p < 0.01) in this group. We found that remifentanil used as the sole agent failed to demonstrate any advantage over the combination of fentanyl/propofol with regard to rapid recovery and discharge following anaesthesia for extracorporal shock wave lithotripsy.