The long-term function of 110 cadaver kidney transplants preserved by hypothermic perfusion was compared with that of 79 fresh cadaver kidneys. The one-month failure rate was 4% in the perfused kidneys in contrast to a 32% one-month failure rate reported by one cooperative group. These data were again confirmed in a prospective, paired study comparing perfused and fresh cadaver kidneys from the same donor. Thus, perfusion of kidneys was not harmful for cadaver transplantation. In fact, of 83 first cadaver transplants, less than 30% of perfused kidneys failed in the first year. There appears to be no evidence supporting the idea that bloodless hypothermic perfusion permanently damages human kidneys or increases the chances of rejection.