We have compared 23 cadaver kidneys preserved with cryoprecipitated plasma (CPP) with 23 consecutive cadaver kidneys preserved with plasma protein fractions (PPF). In both groups the MOX-100 Waters machine was used. The PPF solution does not contain any fibrinogen or gamma globulin. The harvesting characteristics of both groups were comparable. Pulsatile perfusion time in the PPF group was up to 46 hours and in the CPP group was up to 44 hours. In the PPF group, 20 kidneys achieved immediate function upon transplant (85 percent). Two underwent periods of acute tubular necrosis (ATN) and one kidney never worked. In the CPP group, 18 kidneys achieved immediate function (78 percent). Two underwent periods of ATN and three never achieved satisfactory function. From this clinical experience, PPF is as effective as CPP for the preservation of kidneys up to 44 hours prior to transplant. The advantages of the PPF are easy availability, long shelf life, simple preparation, low cost, freedom from risk of hepatitis, and theoretical absence of antibody against the kidney. Graft and patient survival at 6 months showed no statistical difference.