Cardiovascular autonomic neuropathy (CAN) is a common but frequently overlooked complication of diabetes, which can lead to a diverse spectrum of disabling clinical manifestations ranging from mild exercise intolerance to sudden cardiac death. Although traditionally diagnosed using indirect cardiovascular reflex tests, new direct scintigraphic imaging techniques have demonstrated that a cardiac “dysinnervation” can occur early in the course of diabetes, which may have considerable implications for myocardial stability and function. Indeed recent studies have demonstrated that cardiovascular sympathetic tone may be altered very early in the cause of diabetes, and can be associated with altered myocardial blood flow regulation and impaired left ventricular (LV) function. Although convincing evidence has yet to be generated that any therapeutic intervention is capable of reversing CAN complicating diabetes once established, the development and progression of CAN has recently been shown to be sensitive to the simultaneous management of multiple cardiovascular risk factors. This chapter will review the clinical importance of CAN in diabetes, with a particular focus on its impact on the heart.