In an analysis of a series of 186 consecutive first cadaver renal transplants in Newcastle upon Tyne, the most significant finding was the improved graft survival in patients who received pre-transplant blood-transfusion. This apparent benefit was not dependent on the number of units of blood received nor on the interval between transfusion and transplantation. A significant advantage was also shown when there was identity between donor and recipient at the HLA-B locus. This advantage outweighs any disadvantage resulting from the extra time required to transfer kidneys from one centre to another and indeed cold-ischaemia times up to 18 hours did not adversely affect graft survival. It is suggested that the present national distribution of cadaver kidneys in the U.K. is fully justified, but preference should be given to B-locus identity in determining selection.