The influence of ethnicity on outcome of simultaneous pancreas-kidney transplantation (SPK) is poorly defined. After excluding technical failures, we retrospectively reviewed 96 consecutive SPKs (63 Caucasians [C], 33 African-Americans [AA]). All patients received antibody induction, tacrolimus, mycophenolate mofetil, and steroids. One-, 3-, and 5-year actuarial patient survival was similar between C (98%, 95%, 87%) and AA (90%, 90%, 81%), p=NS. One-, 3-, and 5-year kidney graft survival was similar between C (98%, 86%, 81%) and AA (85%, 85%, 78%), p =NS. One-, 3-, and 5-year pancreas graft survival was significantly worse in AA (71%, 68%, 46%) than in C (90%, 85%, 81%), p = 0.008. The cumulative incidence of kidney and pancreas acute rejection (AR) was higher in AA compared with C. Distribution of kidney and pancreas rejection grade was similar between C and AA. AA experienced more pancreas graft losses from early death with functioning graft, AR, and late chronic rejection. The higher incidence of AR and resistance to currently employed induction, maintenance, and antirejection immunosuppression therapies in AA may account for their inferior pancreas graft survival. More aggressive immunosuppression strategies may improve pancreas graft survival in AA but may be associated with increased morbidity and mortality. Further study is warranted.