Diabetes mellitus, a disease which is increasing in prevalence, is a major risk factor for coronary heart disease. In patients following acute myocardial infarction, the presence of diabetes is a powerful risk factor for the development of heart failure, and this intersection of heart failure and diabetes following myocardial infarction carries substantial risk. The poor prognosis associated with heart failure in diabetic patients following myocardial infarction is likely multifactorial. Aggressive strategies for prevention and treatment of heart failure are crucial to reducing the risk associated with diabetes and heart failure following myocardial infarction. This review summarizes epidemiologic, pathophysiologic, and therapeutic data related to diabetes and heart failure in the post-myocardial infarction setting.