A retrospective study was undertaken to evaluate the significance of anatomic variants in living-related donor kidneys, when used in renal transplantation. 301 arteriograms were performed in the evaluation of such potential living donors over an 8-year period. 51 (16.9%) were found to have one or more radiographic abnormalities. 20 of the 51 patients (39%) were judged as not suitable for transplantation because of radiographic abnormalities. 7 of 31 patients who were accepted as organ donors declined for personal reasons. The remaining 24 patients underwent donor nephrectomy with the abnormal kidney utilized as the donor organ. In follow-up, none of the kidneys were lost because of their primary radiographic abnormality, and allograft survival of abnormal kidneys was the same as for normal kidneys transplanted under parallel circumstances. We conclude, in properly selected living donors, kidneys with anatomic variants without pathological significance can be used safely in renal allotransplantation. We do not recommend, however, transplanting kidneys with the potential for the development of progressive disease.