The determination of arterial pressure wave-derived cardiac output (APCO) and central venous O2 saturation (ScvO2) has been introduced as a less invasive procedure for monitoring cardiac function and oxygen delivery. We have used an APCO sensor (FloTracTM) and a monitor for ScvO2 (Vigileo(TM)) in two cases of cardiac valve surgery, where placement of pulmonary artery catheter (PAC) was not applicable due to unfavorable cardiac structure (case 1) and was contraindicated due to an unstable cardiac conduction disorder and arrhythmia (case 2). In case 1, monitoring of APCO was started from the beginning of anesthesia induction and a ScvO2 monitoring central venous catheter was inserted just after anesthesia induction. APCO, ScvO2 and other hemodyanamic information such as arterial BP, CVP, and data obtained from transesophageal echocardiography (TEE) during the pre- cardiopulmonary bypass (CPB) period were measured. APCO and ScvO2 during the post-CPB period showed a reliable correspondence with continuous cardiac output (CCO) and mixed venous O2 saturation (SvO2) as measured by PAC at the end of CPB. In case 2, APCO and ScvO2 were monitored instead of CCO and SvO2. The values of APCO showed a good correlation to intraoperative COs indirectly calculated by the velocity-time integral of the aortic outflow determined in the TEE examination. We experienced that monitoring APCO and ScvO2 is useful for anesthesia management in cardiac valve surgery and can be an alternative to CCO and SvO2 if the placement of PAC and the thermodilution method are not applicable.