People with type 1 diabetes and kidney failure have an increased risk for major adverse cardiovascular events (MACE). Simultaneous pancreas and kidney transplantation (SPKT) improves survival, but the long-term risk for MACE is uncertain. RESEARCH DESIGN AND METHODS We assessed the frequency and risk factors for MACE (defined as fatal cardiovascular disease and nonfatal myocardial infarction or stroke) and related nonfatal MACE to allograft failure in SPKT recipients with type 1 diabetes who underwent transplantation between 2001 and 2015 in the U.K. In a subgroup, we related a pretransplant cardiovascular risk score to MACE. RESULTS During 5 years of follow-up, 133 of 1,699 SPKT recipients (7.8%) experienced a MACE. In covariate-adjusted models, age (hazard ratio 1.04 per year [95% CI 1.01-1.07]), prior myocardial infarction (2.6 [1.3-5.0]), stroke (2.3 [1.2-4.7]), amputation (2.0 [1.02-3.7]), donor history of hypertension (1.8 [1.05-3.2]), and waiting time (1.02 per month [1.0-1.04]) were significant predictors. Nonfatal MACE predicted subsequent allograft failure (renal 1.6 [1.06-2.6]; pancreas 1.7 [1.09-2.6]). In the subgroup, the pretransplant cardiovascular risk score predicted MACE (1.04 per 1% increment [1.02-1.06]). CONCLUSIONS We report a high rate of MACE in SPKT recipients. There are a number of variables that predict MACE, while nonfatal MACE increase the risk of subsequent allograft failure. It may be beneficial that organs from hypertensive donors are matched to recipients with lower cardiovascular risk. Pretransplant cardiovascular risk scoring may help to identify patients who would benefit from risk factor optimization or alternative transplant therapies and warrants validation nationally. Type 1 diabetes affects ;400,000 people in the U.K. (1). Type 1 diabetes significantly reduces life expectancy predominantly because of cardiovascular disease (CVD) complications (2,3). The addition of chronic kidney disease further increases CVD risk (4). We have shown that simultaneous pancreas and kidney transplantation (SPKT)