We report a living related kidney donor incidentally found to have a renal cortical adenoma at nephrectomy. The patient is a 53-year-old man accepted for living related kidney donation. Predonation workup revealed a solitary left renal artery and, on the right kidney, a main artery with a small accessory artery in theupper pole. No other abnormalities were found in the medical history, physical examination, or laboratory and radiological studies. A left laparoscopic nephrectomy was planned. However, during dissection of the upper pole, a 5-mm mass was noted. The nephrectomy was completed, and the organ was preserved in cold University of Wisconsin solution. Permanent section histology showed that the lesion was mostly likely a renal cortical adenoma. As the risk of malignant transformation with immunosuppression could not be adequately determined, the kidney was not transplanted into the recipient. The donor elected not to have the kidney replaced, and the organ was discarded.