Between July 1971 and March 1977, steroid-induced diabetes (SD) developed postoperatively in 31 (10.8%) of 286 nondiabetic adult kidney transplant recipients who were observed for a total of 410 patient transplant years. There was a highly significant association between HLA-A28 and SD. There was no significant association between SD and BB or Bw 15. Age was also associated with SD. However, A28 was associated with SD even when corrected for age. A28 occurred more frequently in blacks than whites, 25.4% and 6.3%, respectively, and accounted for the higher incidence of SD in black adults. There were no significant associations between SD and patients' sex, donor source, number of short-term rejection treatments, or maintenance dose of corticosteroids. Steroid-induced diabetes had no adverse effects on graft or patient survival.