Atherosclerosis and its complications represent the most frequent cause of death in the developed countries. Pathophysiology of the atherosclerosis development has been described in details. Much less is known what is the extent of reversibility of pathophysiological changes. Several angiographic studies have proved that statin administration can slow down the progression of the coronary arteries atherosclerosis. However, only intravascular ultrasound analysis is able to give a detailed description of atherosclerotic plaque development during the treatment with statins. Studies have shown apparent stagnation of atherosclerosis progression and in voluminous plaques also signs of regression. Beside changes in the size of atherosclerotic plaques, alteration in their chemical composition was described. During the treatment with statins, amount of lipids in plaque decreases, which indicates the stabilisation of plaques. Plaques are less prone to a rupture and to the subsequent development of an acute coronary syndrome. Beside statins, which influence namely LDL cholesterol, attention is given to drugs enabling to elevate HDL cholesterol level, because it is the way in which cholesterol is transported from tissues back to the liver. It appears that elevation of HDL cholesterol level could bring about more effective regression of atherosclerotic plaques and together with stagnation of the plaque progression it can significantly improve the conservative methods in the treatment of atherosclerotic disease of the coronary and peripheral arterial system.