OBJECTIVE Evaluation of autonomic function responses is increasingly important for risk prediction and hemodynamic evaluation in the ambulant and perioperative setting, but requires a noninvasive arterial blood pressure measurement device. This study describes whether a novel noninvasive beat-to-beat arterial blood pressure measurement device (Nexfin HD) is able to reproducibly reflect autonomic function responses in healthy volunteers. METHODS Noninvasive beat-to-beat arterial blood pressure measurements (Nexfin HD) were performed in 20 healthy men of 22 ± 3 years. Measurements were performed during supine steady state, controlled breathing (0.125 Hz), passive leg raising, a controlled Valsalva maneuver, and a quick stand test. Finally, relative changes in pulse pressure during autonomic function testing and the test-retest reproducibility were determined. RESULTS Autonomic function tests induced beat-to-beat arterial blood pressure changes that were accurately monitored by the Nexfin device. The intraclass correlation coefficients for systolic and diastolic arterial blood pressure measurements during supine steady state were agreeable [0.91 (0.82-0.96) and 0.84 (0.69-0.93), respectively]. The reproducibility of blood pressure changes during controlled breathing, passive leg raising, and Valsalva maneuver averaged 0.92 (0.82-0.96), 0.76 (0.50-0.90), and 0.94 (0.89-0.97), respectively. The reproducibility of the pulse pressure variation (PPV) as calculated from controlled breathing-induced changes in the arterial blood pressure (13 ± 5%) was high [0.96 (0.93-0.98)]. CONCLUSIONS This study shows that noninvasive beat-to-beat Nexfin HD arterial blood pressure measurements reproducibly reflect autonomic function responses in healthy volunteers.