Blood pressure measurements are one part of a circulatory assessment (Docherty and McCallum 2009). Treatments for raised or low blood pressure may be initiated or altered according to blood pressure readings; therefore correct measurement and interpretation of blood pressure is an important nursing skill. Blood pressure should be determined using a standardized technique in order to avoid discrepancies in measurement (Torrance and Serginson 1996). Both manual and automated sphygmomanometers may be used to monitor blood pressure. The manual auscultatory method of taking blood pressure is considered the gold standard (MRHA 2006), as automated monitoring can give false readings (Coe and Houghton 2002), and automated devices produced by different manufacturers may not give consistent figures (MRHA 2006). So, although automated sphygmomanometers are in common use within health care settings in the UK, the skill of taking blood pressure measurement manually is still required by nurses. As a fundamental nursing skill, blood pressure measurement, using manual and automated sphygmomanometers, and interpretation of findings are often assessed via an OSCE. Within this chapter revision of key areas will allow you to prepare thoroughly for your OSCE, in terms of practical skill and understanding of the procedure of taking blood pressure. Blood pressure is defined as the force exerted by blood against the walls of the vessels in which it is contained (Docherty and McCallum 2009). A blood pressure measurement uses two figures—the systolic and diastolic readings. The systolic reading is always the higher figure and represents the maximum pressure of blood against the artery wall during ventricular contraction. The diastolic reading represents the minimum pressure of the blood against the wall of the artery between ventricular contractions (Doughetry and Lister 2008). You will need to be able to accurately identify systolic and diastolic measurements during your OSCE. When a blood pressure cuff is applied to the upper arm and inflated above the level of systolic blood pressure no sounds will be detected when listening to the brachial artery with a stethoscope. The cuff clamps off blood supply. As the cuff is deflated a noise, which is usually a tapping sound, will be heard as the pressure equals the systolic blood pressure —this is the first Korotkoff ’s sound.