The experience at a single center with 297 consecutive cadaver renal transplants over the past 12 years is reviewed with special attention to acute post-transplant ischemic renal injury (ATN). Sixty-seven patients received kidneys which failed to function immediately (22.5 per cent). Twenty-five (8.4 per cent) never showed any function (NF), and 42 (14.1 per cent) developed delayed function (ATN). The over-all incidence of this complication has exhibited a downward trend in the past 12 years and the possible reasons for this are discussed. The overall rate of patient survival and functional grafts observed for to 12 years by actuarial methods were found to be no different by statistical analysis (ATN versus IF). When patients were subgrouped according to quality of renal function attained by four months post-transplantation, ATN patients with good renal function (serum creatinine levels of less than 2 milligrams per deciliters) demonstrated similar patient and functional graft survival rates when compared with IF patients with similarly good renal function. Thirty-eight per cent of patients with ATN never achieved good renal function (serum creatinine levels of more than 2.0 milligrams per deciliters) and were compared with 8 per cent of IF patients who likewise never achieved good renal function. These two groups were also found to be statistically similar with regard to the rates of patient survival and functional grafts. Thus, it is likely that, although the presence of ATN may predispose a patient to a higher risk of never achieving good renal function, the eventual long term outlook is similar for patients with ATN and those with IF. The most important determining factor in terms of ultimate functional graft survival appears to be relative to the quality of renal function in the early post-transplantation period.