Comorbidity of essential hypertension and type 2 diabetes is a serious problem connected with early affection of target organs and further cardiovascular complications. Pathogenetic mechanisms, determining the progress of essential hypertension, insulin resistance and type 2 diabetes, mostly have mutual symptoms and lead to the progression of disease. Many investigators consider cardiovascular pathology to be disease which has free radical nature. Activation of free radical oxidative process and endothelial dysfunction are recognized one of the most important pathogenetic mechanisms of cardiovascular diseases. To investigate structural and functional changes of heart and vessels, state of the pro- and antioxidant status, levels of proinflammatory cytokines in patients with essential hypertension and type 2 diabetes we have examined 102 patients with essential hypertension stage II and type 2 diabetes in a moderate condition. After the investigation it was discovered that changes of cardiohemodynamics in patients with essential hypertension and type 2 diabetes are characterized by the following aspects: systolic function of left ventricle is conserved, concentric hypertrophy of left ventricle predominates and also there is diastolic dysfunction similar to disordered relaxation. Changes of blood vessel walls in the examined patients are shown by growing intima-media thickness and pulse wave velocity in carotid artery and aorta and also by dropping endothelium dependent vasodilation. The mentioned structural and functional changes in heart and magistral vessels go together with growing levels of cytokines, activation of pro-oxidant system with suppression of antioxidant system, what is shown by correlation connections of different intention and direction.