We investigated graft and patient survival implications of simultaneous pancreas kidney (SPK) transplant from old donors. Data describing patients with type 1 diabetes mellitus listed for an SPK transplant from 1994 to 2005 were drawn from Organ Procurement and Transplant Network registries. Allograft survival, patient survival and long-term survival expectations among SPK recipients from young (age <45 years) and old (age >/=45 years) donors were modeled by multivariate regression. We also examined predictors of reduced early access to young donor transplants. Of 16 496 eligible SPK candidates, 8850 patients (53.6%) received an SPK transplant and 776 (8.8%) of these transplants were from old donors. Reasonable 5-year, death-censored kidney (77.8 %) and pancreas (71.3%) survivals were achieved with old donors. SPK transplantation from both young and old donors predicted lower mortality compared to continued waiting. An additional expected wait of 1.5 years for a young donor equalized long-term survival expectations to that achieved with use of old donors. Early allocation of young donor transplants declined in the more recent era and varied by region, candidate age, blood type and sensitization. We conclude that old SPK donors should be considered for patients with decreased access to young donor transplants. Prospective evaluation of this practice is needed.