Parameters of early failure in kidney transplantation have been analyzed from 507 transplantations with transplant loss in the first month, selected among the 7541 cadaveric kidney transplantations performed in France between 1985 and 1989. These failures represent 6.7 percent of the population transplanted over this period of time, 68.6 percent of the failures that occurred in the first 3 months post-grafting, and 47 percent of the total number of the first year failures. Comparing patients with and without transplant failure in the first month, sex of the donor and the recipient, ABO group of the donor and the recipient, origin of the kidney, cold ischemia time, HLA compatibility, dialysis duration, number of previous transplantations, showed no influence on the occurrence of early failure. Three parameters appeared to be significant risk factors: donor's age less than 5 years, P = 0.00001; recipient's age less than 5 years, P = 0.05; pregraft immunization, P = 0.002. Furthermore, multifactorial analysis showed that the absence of HLA compatibilities between donor and recipient in hyperimmunized patients also has a significant influence on early graft loss. However, comparison of these same parameters in patients with transplant failure within the first month and between 2 and 12 months post-grafting revealed that the influence of these 4 significant parameters is longstanding and that none of them is specific of the precocity of graft loss.