Collins' solution is one of the world-wide methods used for kidney preservation. A long-term survey of transplanted kidneys thus preserved has never been reported. Clinical, biologic, radiologic, and pathologic data collected from 225 cadaver kidney transplantations were analyzed according to the total ischemic time (group 1: TIT less than or equal to 12 hr; group 2: TIT 12-30 hr). No differences could be demonstrated between the two groups, whether considering the percentage of immediate function, the serum creatinine level that was normal up to 2 years, the incidence of abnormal blood pressure, the pathologic changes on routine biopsies performed at 6 months and 2 years, or arteriographic features at 2 years. A better graft survival rate was consistently found at 6 months, 1 year, and 2 years when TIT was between 12 and 30 hr. This could be related to the higher incidence of well-matched kidneys in this group of patients, thereby emphasizing the efficiency of exchange programs for compatible kidneys.