IntroductionThe prevalence of obesity in older patients undergoing kidney transplantation is increasing. Older age and obesity are associated with higher risks of complications and mortality post-transplantation. The optimal management of this group of patients remains undefined. MethodsWe retrospectively analyzed the UNOS database of adults ≥70 years of age undergoing primary kidney transplant from 1/1/2014 to 12/31/2022. We examined patient and graft survival stratified by body mass index (BMI) in three categories, <30, 30-35, and >35. We also analyzed other risk factors that impacted survival. ResultsA total of 14,786 patients ≥70 years underwent kidney transplantation. Of those, 9,731 patients had a BMI <30, 3,726 with BMI 30-35, and 1,036 with BMI >35. During the study period, there was a significant increase in kidney transplants in patients ≥ 70 years old across all BMI groups. Overall, patient survival, death-censored graft survival, and all-cause graft survival were lower in obese patients compared to non-obese patients. Multivariable analysis showed worse patient survival and graft survival in patients with a BMI of 30-35, a BMI >35, a longer duration of dialysis, diabetes mellitus, and poor functional status. ConclusionAdults ≥70 years should be considered for kidney transplantation. Obesity with a BMI of 30-35 or >35, longer duration of dialysis, diabetes, and functional status are associated with worse outcomes. Optimization of these risk factors is essential when considering these patients for transplantation.