Because the safety of living organ donors is essential, we have been performing donor kidney biopsy before donation in cases where decision-making regarding suitability is marginal. To clarify the degree to which pathological change in the kidney can be predicted on the basis of clinical data obtained non-invasively, we analyzed preexisting lesions found by one-h biopsy in 76 living kidney donors, and compared the findings with clinical parameters at the time of donation. Pathological change in living kidney donors was correlated to some extent with predonation clinical parameters including age, serum creatinine, estimated glomerular filtration rate and presence of hypertension, while the lesions influenced by glucose intolerance were not completely correlated with the results of oral glucose tolerance test. A follow-up study will be required to determine whether these mild histological findings at the time of donation influence long-term outcome in the donor.