In eight patients undergoing cardiac surgery for aortic and/or mitral valvular disease, mean arterial blood pressure (MAP), central venous pressure (CVP), cardiac index (CI), stroke index (SI), pulmonary capillary wedge pressure (PCWP), and pulmonary arterial mean pressure (PAMP) were measured after premedications with diazepam-scopolamine (I), after breathing 100% oxygen (II), and on controlled respiration (III) after induction of anaesthesia with enflurane-O2, and endotracheal intubation facilitated by succinylcholine. All measurements were done prior to surgery. Enflurane anaesthesia was found not to affect cardiac index. The average SI decreased by 27%, but was compensated for by an average increase in heart rate (HR) of 33%. The average systemic vascular resistance (SVR) decreased by 14%. All other measured parameters were found to be unaffected by enflurane-O2 anaesthesia. It is concluded that the cardiovascular stability observed in healthy young normals during enflurane anaesthesia is preserved in patients with moderate to severe heart failure, making enflurane an anaesthetic agent well suited for patients with cardiac disease.