Contribution of chronic renal allograft vascular changes to the long-term graft function and its relationship with maintenance immunosuppression is incompletely understood. Therefore, we conducted a retrospective, single- center study in 163 kidney, or kidney-pancreas recipients, who had implantation and 12-month protocol biopsy, to assess relationship between renal vascular changes and renal function up to three years post-transplant. Immunosuppression consisted of tacrolimus and mycophenolate ± steroids. Renal histology was interpreted according to the Banff classification. Glomerular Filtration Rate (eGFR) was estimated using MDRD formula. In a multivariate analysis, 12-month arterial fibrointimal thickening (cv), but not arteriolar hyalinosis (ah) independently correlated with lower eGFR up to 3 years post-transplant. A lower 12-month cv was independently associated with lower implantation ah score and with higher average first-year posttransplant MMF dose. In multiple logistic regression, an increase in cv was less likely with younger donor age, and with higher average first-year MMF dose. 12-month ah independently correlated with ah at implantation and with donor age. First-year increase in ah was more likely in recipients of older kidneys and with lower implantation ah scores. In conclusion, the 12-month cv and its first-year posttransplant increase, may be independent predictors of GFR. Intensified MMF dosing during first post-transplant year may decrease progression of renal arterial fibrointimal thickening.