Donor age is a significant risk factor for graft loss after kidney transplantation. We investigated the question whether significant graft years were being lost through transplantation of younger donor kidneys into older recipients with potentially shorter lifespans than the organs they receive. We examined patient and graft survival for deceased donor kidney transplants performed in the United States between the years 1990 and 2002 by Kaplan-Meier plots. We categorized the distribution of deceased donor kidneys by donor and recipient age. Subsequently, we calculated the actual and projected graft survival of transplanted kidneys from younger donors with the patient survival of transplant recipients of varying ages. Over the study period, 16.4% (9250) transplants from donors aged 15-50 were transplanted to recipients over the age of 60. At the same time, 73.6% of donors above the age of 50 were allocated to recipients under the age of 60. The graft survival of grafts from younger donors significantly exceeded the patient survival of recipients over the age of 60. The overall projected improvement in graft survival, by excluding transplantation of younger kidneys to older recipients, was approximately 3 years per transplant. Avoiding the allocation of young donor kidneys to elderly recipients, could have significantly increased the overall graft life, by a total 27 500 graft years, between 1990 and 2002, with projected cost savings of about 1.5 billion dollars. Copyright © Blackwell Munksgaard 2005.