In the last two decades, there is a radical change in the approach to the vascular endothelium. Nowadays, it is not only the monolayer of cells, as thought 20 years ago, but also the largest human endocrine organ with crucial role inmaintaining vascular homeostasis. Dysfunction of endothelial cells as seen in hypertension, diabetes mellitus, hyperlipidemia or smoking is the first, but reversible step in atherogenesis. Hence, early diagnosis and treatment of endothelial dysfunction may lead to decreasing of cardiovascular morbidity and mortality in the population.

        Key words: endothelium, atherosclerosis, prevention