Clinical assessment of a patient, monitoring the progress of a condition, and/or titration of a therapy is dependent on the metrological characteristics of diagnostic equipment. While metrological performance of instruments is commonly assessed in research, it is not so often done in clinical practice. Physical rehabilitation applications may benefit individuals with mental health concerns and are associated with an accurate analysis of balance and gait. There is a paucity of published data regarding the metrological characteristics of commonly used clinical instruments used in posturographic measurements. We desired to assess the accuracy, trueness, precision and resolution of four posturography systems that we use clinically in practice: a Bertec BP-5050, a Vestibular Technologies CAPS® Professional and a Vestibular Technologies CAPS® Lite threecomponent balance platforms, and a NeuroCom® Balance Manager SMART EquiTest®. Metrological performance by posturography instruments was recommended in 2013 by the International Standardization Committee for Clinical Stabilometry of the International Society for Posture and Gait Research (ISPGR). Clinical and research findings may be erroneous, or at the least misleading, if the instruments used to make clinical decisions are associated with significant error. We suggest that there is a strong need for posturographic instrumentation with appropriate metrological characteristics used in clinical applications. The ISPRG recommendations appear to be reasonable and appropriate, and our results show they are obtainable. Physical measurements and functional testing used to correlate and design mental health and physical based rehabilitation strategies are often dependent upon the accuracy and metrological integrity of diagnostic instruments used in posturography.