Background: Transplantation of kidneys retrieved from extended criteria donors is one of the options to expand the pool of available grafts, shorten the waiting time and increase the availability of this method of treatment. However, some factors (eg, donor age) may impair the results of transplantation. Material/Methods: This study was a retrospective assessment of 327 patients who underwent renal transplants during the period 1995-2005, with kidneys harvested from expanded criteria donors (ECD) as defined by the United Network for Organ Sharing (UNOS). They formed 2 groups: group 1 (ECD - younger, n=255) consisted of recipients of kidneys obtained from donors aged 50-59 years; group 2 (ECD - older, n=72) consisted of patients who received kidneys from donors >60 years old. An analysis of the 1-, 3- and 5-year survival of grafts and patients and evaluation of graft function were performed. Results: graft survival was significantly better in group 1 (ECD-younger) vs. group 2 (ECD-older), as was renal graft function. Survival 3 and 5 years after transplantation was 87.7% vs. 81.9%, 73.1% vs. 66.6%, and 60.1% vs. 51.7%, respectively. Delayed graft function occurred significantly more frequently in group 2 (group 1 vs. group 2-28.8% vs. 34.6%, p=0.0001). Conclusions: The transplantation of kidneys obtained from older donors fulfilling ECD definition is associated with shorter graft survival, deteriorated function and more frequent renal delayed graft function. However, this did not increase the mortality of recipients.