Increased aortic stiffness is a major factor responsible for the high cardiovascular mortality in patients with end-stage renal disease, but the impact of kidney transplantation on recipient aortic stiffness remains poorly defined. The use of expanded-criteria kidney donors is associated with decreased recipient survival compared with the use of standard-criteria donors, although the underlying mechanisms are incompletely understood. It was hypothesized that donor characteristics may affect recipient aortic stiffness, which may contribute to cardiovascular mortality in these patients. Aortic stiffness was evaluated by measurement of carotid-femoral pulse wave velocity in 74 cadaveric kidney recipients at 3 and 12 mo after transplantation. At 3 mo, aortic stiffness was associated exclusively with recipient-related factors: Age, gender, and mean BP. At 12 mo, age of the donor kidney emerged as an additional determinant. The change in aortic stiffness between 3 and 12 mo strongly correlated with donor age; stiffness improved in recipients of young kidneys (first tertile of donor age) and worsened in recipients of older kidneys (upper tertile of donor age). At 12 mo, the carotid-femoral pulse wave velocity was >1 m/s higher in recipients of the oldest kidneys than in the recipients of younger kidneys. The association between donor age and aortic stiffness was independent of recipient age, gender, mean BP, pretransplantation dialysis duration, conventional cardiovascular risk factors, medication, posttransplantation events, and GFR. These results demonstrate that the impact of kidney transplantation on recipient aortic stiffness is dependent on donor age and suggest that ongoing damage to large arteries might contribute to the mechanism underlying the association of old-donor kidneys and increased cardiovascular mortality.