Patient and kidney survival rates were compared between 69 diabetic patients undergoing simultaneous kidney-pancreas transplantation (group 1) and 723 nondiabetic patients undergoing kidney transplantation (group 2). The patients were treated with different immunosuppressive regimens over the years: steroids plus antilymphocyte globulin (ALG) plus azathioprine (Aza); cyclosporin A (CsA) plus ALG; steroids plus ALG plus Aza, replacing Aza 1 mo posttransplantation; or low doses of steroids plus CsA plus Aza. One-year kidney survival rates with the different regimens were 50, 42, 54, and 76%, respectively, in group 1 and 71, 74, 78, and 84%, respectively, in group 2. Patient survival was 60, 57, 71, and 86%, respectively, in group 1 and 93, 95, 94, and 96%, respectively, in group 2. Differences between the two groups were statistically significant for the first three protocols but not for the one used in this study. In group 1, 38 patients (55%) had a functioning kidney graft, whereas 15 (21%) lost their kidney to rejection. Between these two patient categories, there was no significant difference in age, sex, duration of diabetes, time on dialysis, blood transfusion number, HLA immunization, or HLA matching. Thus, since 1984, kidney-graft survival has not been inferior in diabetic patients. This improvement is mainly due to a decreased mortality related to better patient preparation and improvement in immunosuppression.