Performance qualification of the United States Pharmacopeia (USP) paddle apparatus (USP apparatus 2), as described in USP General Chapter <711> Dissolution, requires a demonstration of the dissolution behavior of a standard material as well as control of the mechanically measurable parameters of the apparatus. The USP performance verification test (PVT), an integral part of <711>, plays an important role in demonstrating the apparatus suitability and addressing the interlaboratory variability of dissolution results by using a standard procedure and reference standard material. The USP has used a specially formulated tablet containing prednisone in the role of the reference standard material that has been shown to be sensitive without undue variability. This paper describes how the use of the PVT ensures the accuracy of dissolution results by understanding and controlling the variability. This paper provides an overview of the following: the dissolution test; the mechanics of the test and associated hydrodynamics; the PVT reference standard; PVT and mechanical qualification.