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 (FloTrac™) and a monitor for ScvO₂ (Vigileo™) 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 precardiopulmonary 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.