Cadaveric kidneys are sometimes unsuitable for transplantation because of possible ischaemic damage. The advent of perfusion preservation machines has enabled evaluation of perfusion characteristics and perfusate changes of organs prior to transplantation. This study has evaluated the changes in perfusate pH, lacate dehydrogenase, lactate and free fatty acid utilization in an attempt to identify those kidneys with ischaemic damage. In this investigation no single factor was discriminatory and it was not possible to predict with any degree of certainty those kidneys liable to delayed function or to non-function.