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Purpose: The ejection duration (ED) is an important indicator of ventricular function as well as ventriculo-arterial coupling. Thus, the non-invasive oscillometric determination of ED from arterial pressure waves could enhance methods of pulse wave analysis. The aim of this work was to test and to validate the calculation of ED based on measurements from two different devices (brachial oscillometry and radial tonometry). Methods: 138 pulse wave measurements from 79 patients were obtained in direct succession with the Mobil-O-Graph (IEM, Germany) and with the Sphygmocor device (At Cor Medical Pty. Ltd., Australia) in a comparative study. An algorithm based on numerical derivatives was developed to determine the ejection duration from the arterial pulse wave. For both measurements, the ED was calculated and the ED from the internal algorithm of the Sphygmocor was obtained. Results: The mean ED of the internal Sphymocor algorithm (SphyInt) is 309+–27 ms, of the calculated ED from the Mobil-O-graph measurements (Mob) 304+–29 ms and of the calculated ED from the Sphygmocor recordings (Sphy) 308+–30 ms. So, the mean differences between Mob and SphyInt are −4+–20ms, see figure, and between Mob and Sphy are −3+–26ms. The sampling rates of Sphymocor and Mobil-O-Graph are 128 respectively 100 Hz, so the mean errors are below the particular step sizes. Conclusion: The algorithm for calculation of the ED was tested successfully on radial and brachial recordings. As the differences between locations as well as between algorithms are sufficiently small, the determination of ejection duration from brachial oscillometric pulse waves seems feasible.