For many years new-onset diabetes after transplantation has been recognized as a complication of solid-organ transplantation, although its importance has been greatly underestimated. Studies have shown that the cumulative incidence of this condition in heart transplant recipients may reach 32% at 5 years, similar to that reported in kidney and liver transplant patients. Several factors predispose to increased risk for developing new-onset diabetes after transplantation, including age, ethnicity, family history of diabetes, obesity and immunosuppressive therapy. Corticosteroids are associated with the greatest risk of developing the condition. Tacrolimus is more diabetogenic than cyclosporine in kidney and liver transplant patients, but there are few data reporting the effects of these agents in heart transplant patients. In kidney transplant patients, diabetes is known to be a significant risk factor for cardiovascular disease post-transplant. Although this has yet to be demonstrated clearly in heart transplant patients, evidence suggests that new-onset diabetes after transplantation may play a role in the development of cardiac allograft vasculopathy (CAV). Because CAV is the major limitation to long-term survival in this population, it is clear that efforts should be made to reduce the risk of diabetes and treat this condition appropriately. Management of transplant recipients with new-onset diabetes after transplantation has been assisted by the recent publication of International Consensus Guidelines. The guidelines were developed to establish a standard definition and describe risk factors for new-onset diabetes after transplantation. Use of these guidelines will help to prospectively identify those at risk of developing new-onset diabetes after transplantation so that therapeutic strategies can be individualized early in the treatment regimen. These management approaches should help to lower the risk of new-onset diabetes after heart transplantation and reduce the possible long-term consequences of the condition.