"Zero-hour" biopsies of 65 donors have been performed since 1994. Donor kidneys were categorized into five groups based on the morphological findings in "zero-hour" biopsies. No morphological abnormalities were found in 38% of the cases (group 1). Arteriosclerosis was present in 31% of donor kidneys (group 2). Specific morphological alterations, i.e. acute tubular necrosis [21.5%], tubulointerstitial nephritis [6.2%] or glomerulonephritis [3.1%] were detectable in the cases remained (group 3-5). During an average of 336 posttransplant days clinical and histological follow up was performed (50 rebiopsies). Statistical data of mismatch (1.4-2.0), average of donor/recipient age (35-42 years), cold and warm ischaemic time (1290 and 66 min) were comparable in all groups. According to our observations: 1. higher creatinin was found in grafts with arteriosclerosis (group 2) (p < 0.05), 2. there were more non-viable grafts and longer period of delayed graft function in acute tubular necrosis (group 3), 3 higher creatinin, rejections with the need of rehemodialysis were observed in four cases of tubulointerstitial nephritis (TIN-group 4). Glomerulonephritis (GN-group 5) grafts had only delayed graft function, however these groups were few for statistical evaluation. Biopsy complication in 1/115 cases was found (rebiopsy induced kidney haemorrhage). In conclusion, "zero-hour" biopsies can be useful and safe tools to predict early graft function. Besides "zero-hour" biopsies help the histological interpretation of consecutive graft rebiopsies.