Diabetes mellitus is a chronic disorder that affects predominantly the carbohydrate metabolism, but also the biotransformation of proteins and fat. Many intra- and extracellular metabolic mechanisms are impaired which leads to structural changes in the vascular wall and the heart muscle. This eventually causes their functional deterioration and the end result is clinical manifestation of macrovascular incidents or heart failure. People with perturbations of the glucose metabolism (impaired fasting glucose, impaired glucose tolerance and insulin resistance) are also with a higher risk of cardiovascular diseases, even before the diagnosis of diabetes. Nowadays we have a cheap, easy and non-invasive method for early diagnosis of cardiovascular disorders, way before their clinical manifestation, and that is the ultrasound methodology. The echocardiography is a valuable technique for the detection of changes in the myocardial structure and its contractility. The tissue Doppler ultrasound is a more precise method that can detect the slightest aberrations in the heart muscle function, that could not be seen with the conventional echocardiography. Subclinical atherosclerotic changes can be determined with a Doppler scan of the big arteries (carotids, renal arteries), and the subsequent calculation of their resistive index and of the intima-media thickness. There are a lot of studies in this field which show that the structural and functional impairment could be diagnosed in diabetic patients without any complaints and with otherwise healthy hearts. This means that these diagnostic methods should be used in the routine clinical examination of every diabetic individual in order to predict and possibly prevent major cardiovascular events and severe heart failure.