Diabetes mellitus remains a relative contraindication to heart transplantation. From June 1985 to December 1987, 71 patients underwent heart transplantation. Fifty-seven patients were nondiabetic, and nine had preexisting diabetes mellitus. Four patients were insulin dependent and three were not. All operative survivors (66) from these two groups were compared for survival and numbers of rejection and infection. Actuarial survival in the group with diabetes mellitus was 100% and 97.7% in the group without diabetes. Immunosuppression was maintained with cyclosporine, azathioprine, and low-dosage prednisone. In the group with diabetes two patients were maintained without prednisone. Selected diabetic patients can have successful transplantations. There is no significant difference in survival between the diabetic and nondiabetic patient. There is a tendency toward more rejections and fewer infections among the diabetic patients. In our experience diabetes mellitus is not a contraindication to heart transplantation.