INTRODUCTION The purpose of this study was to determine whether incidentally discovered, small renal cell cancers (RCC) in donor kidneys can be excised and safely transplanted. METHODS The Israel Penn International Transplant Tumor Registry database was searched and all small RCC that were identified and resected prior to transplantation of deceased and living donor kidneys were reviewed. Patient demographics, tumor characteristics, recurrence, and survival were examined. RESULTS Fourteen kidneys were identified in which small RCC were noted at the time of procurement and where the tumors were excised ex vivo and then transplanted. Eleven kidneys were obtained from living related donors and three were from deceased donors. Median tumor size was 2 cm (range 0.5 to 4 cm). All 14 tumors were of histological Furhman grade II/VI (n = 8) or Furhman grade I/VI (n = 6). All kidneys had pathologically confirmed negative margins. The mean age of the recipients was 40.8 +/- 9.2 years, with the majority being men (11 men; 3 women). Median follow-up for this group was 69 months (range 14 to 200 months). There have been no recurrences of tumor in these recipients and the 1-, 3-, and 5-year patient and graft survivals are 100%, 100%, and 93%. CONCLUSIONS These data represent the only data available (to our knowledge) on this issue. This experience indicates that donor kidneys with small, incidental RCC and low histological grade (Furhman grade I and II/IV) can be managed with excision and transplantation, with a low risk of tumor recurrence in the recipient.