Central blood pressure waveforms contain specific features related to cardiac and arterial function. We investigated posture-related changes in ventriculo-arterial hemodynamics by means of carotid artery pulse wave analysis. ECG, brachial-cuff pressure and common carotid artery diameter waveforms (by M-mode ultrasound) were obtained in 21 healthy volunteers in supine and sitting position (age 19-30; male/female: 10/11). Pulse wave analysis was based on a timing extraction algorithm which automatically detects acceleration maxima in the second derivative of the CA pulse waveform. The algorithm enabled determination of isovolumic contraction and ejection periods (supine; ICP: 43 ± 8 ms, 4 ms precision; EP: 302 ± 16 ms, 5 ms precision; mean ± SD). Compared to supine, in sitting position diastolic blood pressure (DBP) increased by 7 ± 4 mmHg (p<0.001) and R-R interval decreased by 49 ± 82 ms (p=0.013), reflecting normal baroreflex response, while EP decreased to 267 ± 19 ms (p<0.001). Shortening of EP was significantly correlated to earlier arrival of the lower body peripheral reflection wave (r²=0.46, p<0.001). ICP increased by 7 ± 7 ms (p<0.001), ICP/EP increased from 14 ± 3% (supine) to 19 ± 3% (p<0.001) and DBP/ICP decreased by 7% (p=0.023). These results suggest that orthostasis causes a decrease in left ventricular output due to arterial wave reflections and presumably reduced cardiac preload. We conclude that carotid artery ultrasound and pulse wave analysis enable non-invasive quantification of ventriculo-arterial responses to changes in posture.