Metabolic syndrome and diabetes are associated with increased risk of cardiac dysfunction independently of underlying coronary artery disease. The underlying pathogenesis is partially understood but accumulating evidence suggests that alterations of cardiac energy metabolism might contribute to the development of contractile dysfunction. Recent findings suggest that myocardial mitochondrial dysfunction may play an important role in the pathogenesis of cardiac contractile dysfunction in type 2 diabetes. This review is focused on evaluating mechanisms for the mitochondrial abnormalities that may be involved in the development and progression of cardiac dysfunction in diabetes. (KOREAN DIABETES J 32:467-473, 2008)