The gold standard for cadaveric renal preservation is cold static storage (CS) using the University of Wisconsin solution (UW). Up to the present time, new preservation solutions have not been able to significantly improve preservation quality of donor grafts. Recently Polysol (PS), a colloid based preservation solution with a low viscosity has been developed. The efficacy of PS has been demonstrated in machine perfusion preservation studies of the rat liver and CS preservation of the rat small bowel. To compare Polysol and UW for CS preservation of kidney grafts using a porcine autotransplantation model. German Landrace pigs (21-28 kg) were subjected to a left nephrectomy. Kidney grafts were perfused with 500 ml of PS (n=6) or UW (n=6) followed by 20 hrs CS. The preserved kidneys were thereafter transplanted and the contralateral kidneys removed. Urine was collected through a urethrocutaneostomy. Renal function was assessed daily by serum creatinine, serum urea and urine production. Seven days post-transplant, animals were sacrificed and the transplanted kidneys removed for histological evaluation. All aminals survived for 7 days and delayed graft function did not occur. Serum creatinine, peak-creatinine, serum urea and peak-urea values post-transplant were all significantly lower in the PS preserved grafts (p=0.041, p=0.018, p=0.044, p=0.049, resp.). Urine production did not differ significantly. The PS preserved kidney grafts showed overall less inflammatory infiltration, tubular damage and edema, although not significant. Using Polysol, renal function was significantly improved after 20 hours CS compared to UW solution in a porcine autotransplantation model.