BACKGROUND: Early immunologic and non-immunologic injury of renal allografts adversely affects long-term graft survival. Some degree of preservation injury is inevitable in cadaveric renal transplantation, and, with the reduction in early acute rejection, this non-immunologic injury has assumed a greater relative importance. Optimal graft preservation will maximize the chances of early graft function and long-term graft survival, but the best method of preservation pulsatile perfusion (PP) versus cold storage (CS) is debated. METHODS: Primary cadaveric kidney recipients from January 1990 through December 1995 were evaluated. The effects of implantation warm ischemic time (WIT) ( < or = 20 min, 21-40 min, or > 40 min) and total ischemic time (TIT) ( < or > or = 20 h) on death-censored graft survival were compared between kidneys preserved by PP versus those preserved by CS. The effect of preservation method on delayed graft function (DGF) was also examined. RESULTS: There were 568 PP kidneys and 268 CS kidneys. Overall death-censored graft survival was not significantly different between groups, despite worse donor and recipient characteristics in the PP group. CS kidneys with an implantation WIT > 40 min had worse graft survival than those with < 40 min (p = 0.0004). Survival of PP kidneys and those transplanted into 2 DR-matched recipients was not affected by longer implantation WIT. Longer TIT did not impact survival. DGF was more likely after CS preservation (20.2% versus 8.8%, p = 0.001). CONCLUSIONS: Preservation with PP improves early graft function and lessens the adverse effect of increased warm ischemia in cadaveric renal transplantation. This method is likely associated with less preservation injury and/or increases the threshold for injury from other sources and is superior to CS.