The method for rapid evaluation of automatic blood pressure (BP) measurement devices (READ) is based on numerous BP measurements at rest and during a standardised postural challenge in a small number of subjects with a wide range of BPs. The present study proposes additional parameters of the READ for in-field validation of automatic BP measurement devices. BP measurements were done in supine position for 10 min followed by head-up tilt for 30 min and again supine for 10 min. BPs were determined simultaneously by automatic (AU) and mercury sphygmomanometric (MS) measurements on the same arm. The BP differences ⌬BP:AU-MS were calculated. Three units of the Colin BP-8800 and the Datex-Engstrom Cardiocap ™ II were evaluated. Based on ⌬BP(AU-MS), the grade of accuracy, aberration patterns and correlates of accuracy were assessed for each unit. Per unit, an average of 121 measurements were done, every BP category being met in у20 MS measurements. In general, the AU systolic BP