Haemodynamic variables were measured following administration of pipecuronium 70 micrograms.kg-1 and pancuronium 90 micrograms.kg-1 (approximately equivalent to 1.5 x ED95) in patients anaesthetised with fentanyl 50 micrograms.kg-1 and scheduled to undergo coronary artery bypass grafting. There were significant increases in heart rate (22%), mean arterial pressure (10%), cardiac index (16%), and the rate pressure product (35%) following administration of pancuronium. The absolute values of these parameters were, however, within acceptable clinical limits. Administration of pipecuronium produced minimal and insignificant changes in these parameters. Other measured or derived indices showed only small changes with both agents and these were generally insignificant. There were no incidences of significant bradycardia following pipecuronium administration. The results from the present study suggest that pipecuronium would have advantages for use in patients with significant cardiovascular disease.