Diabetes mellitus is, as compared with the non-diabetic population,associated with a much higher mortaliy of ischaemic heart disease and other cardiovascular diseases. In this risk participates in a major way also diabetic dylipidaemia.The latter is characterized in particular by hypertriglyce- ridemia which reflects the increase of VLDL and IDL lipoproteins. Elevated and prolonged po- stprandial lipaemia participates in the develoment of qualitative lipoprotein changes. Highly athergenic „small dense LDL“ are formed which are liable to an oxidative modification and are then in an unregulated manner taken up in the vascular wall. Reduction of HDL-cholesterol and a change in the different HDL sub-populations leads then to a deteriorated reverese cholesterol transport. Type 2 diabetes mellitus is associated with dyslipidaemia in the majority of patients even under conditions of satisfactory compensation of diabetes, in particular during the postprandial stage. On the other hand, in type 1 diabetes the lipid values usually become normal when the blood sugar level becomes normal, however qualitative changes of lipoproteins frequently persist. In- creased glycation and oxidation of lipoproteins is a common sign of both types of diabetes. For prevention of cardiovascular complications treatment of diabetic dyslipidaemia is at least equally important as efforts to achieve optimal compensation of diabetes. Successful treatment of diabetic dyslipidaemia includes efforts to achieve comepensation of dia- betes, optimation of body weight, increase of physical activity, modification of diet, treatment of other secondary causes of hyperlipidaemia, and if these provisions are not successful, pharmaco- logical hypolipidaemic treatment. The risk of macrovascular complications is so high in diabetics that according to recent knowledge it is not necessary to differentiate between primary and secondary prevention but aggressive treatment is necessary to achiebe target values of total cholesterol < 5.0 mmol/l and LDL-cholesterol < 3.0 mmol/l. Triglycerides > 2 mmol/l and HDL-cho- lesterol <1mmol/l are signs of a high cardiovascular risk. Optimation of the whole lipid profile is ideal.

        Key words: Diabetes mellitus - Dyslipidaemia.