In the design of high speed piezoelectric pressure probes the criterion of matching the acoustic impedance of elements in the stress transmission system composed of piezoelement and backing rod is found to be inconsequential. Analysis and empirical evaluation of a typical probe configuration indicate that optimum probe performance can be achieved by utilizing backing rod material with minimum lateral strain (&ngr;/E) characteristics so as to serve effectively to damp induced radial stress oscillations in the piezoelement.