Improvement in sensing technologies is leading to new, accurate noninvasive monitoring devices. However, noninvasive continuous blood pressure (BP) monitoring still faces many challenges, such as: patient's movement, device accuracy and consistency. In this study, the accuracy of a novel noninvasive BP measuring system based on a three-axis force sensor is compared with the invasive arterial cannula taking 21 simultaneous measurements mostly on elderly, postsurgical participants. For the simultaneously recorded invasive and noninvasive signals, the similarity was high, the average correlation was 0.9001 ± 0.0588. The average differences (±SD) for simultaneously recorded systolic, diastolic and mean arterial pressures were: -9.53 ± 4.69, -0.26 ± 3.06 and 1.25 ± 2.26 mmHg, respectively. The results of diastolic and mean arterial pressure satisfy the criteria set by the Association for the Advancement of Medical Instrumentation. These results suggest that this noninvasive system could be a useful tool in continuous noninvasive BP monitoring, but still requires development.