Most of the automated non-invasive blood pressure (NIBP) monitors in clinical use rely on the oscillometric technique for measuring the blood pressures. The functional evaluation of these monitors has relied on comparison with intra-arterial blood pressure measurements or comparison with‘standard’non-invasive blood pressure meters such as the Hawksley random zero sphygmomanometer. The commercial availability of simulated arm test instruments provides the opportunity for developing an alternative evaluation method. We describe the control of an NIBP simulator by a personal computer which is also linked to the NIBP monitor under test. An evaluation protocol is described and the data analysed to present graphically and in tabular form an assessment of the NIBP monitor.