Diabetes mellitus as a disease of epidemiological impact leads to diabetic cardiopathy by modulation of myocardial, vascular and metabolic components. This includes the development of a coronary microangiopathy and a decrease of diastolic and systolic function of the left ventricle as well as the development of an autonomic diabetic neuropathy. Patients with diabetes show an increased mortality concerning cardiovascular events. They more often suffer from myocardial infarction as non-diabetics mostly with a more serious course. Moreover, the post-infarction course is affected with a worse prognosis as in non-diabetics. For diagnosis of cardial involvement in diabetes electrocardiographic and echocardiographic procedures are of use. Special tests of the autonomic function complete the diagnostic ensemble. An early therapy with ACE-inhibitors and beta blocking agents as well as a strong diabetes therapy, in particular with insulin, can influence the mortality favorably. Moreover, the diagnosis and therapy of additional cardiovascular risk factors (arterial hypertension, dyslipidemia) are very important, because these are correlated with a for diabetic patients markedly increased risk of mortality. The clinical relevance of the term diabetic cardiopathy is justified by the 6 factors: macroangiopathy, microangiopathy, disturbances of the myocardial metabolism, myocardial fibrosis, autonomic diabetic neuropathy and disturbances of the coagulability. Diagnostic and therapeutic goals are discussed.