Renal wedge biopsies were taken from donors' kidneys immediately at the end of cold ischaemia and 30min after transplantation in 11 cases. Five renal grafts showed immediate and six showed delayed renal function clinically. The ratio of apoptotic and necrotic renal tubular cells and Ki67 activity was determined in both biopsies. Necrotic and apoptotic as well as proliferating renal tubular cells were seen in all samples. Both apoptotic and proliferative activity was decreased in samples taken 30min after transplantation in cases of immediate renal function compared to the samples taken before transplantation. This phenomenon was not observed in cases of delayed renal function.