Low-density lipoproteins (LDLs) having various modifications are known to be atherogenic, i. e., possessing ability of inducing atherosclerosis. Circulating modified LDLs (cmLDLs) were found in blood of patients diagnosed with atherosclerosis confirmed angiographically. They appear to contain 2-3-fold less sialic acid as compared to LDLs in blood of apparently healthy people; cmLDLs differ by their physical properties: having higher density, smaller diameter, and greater electronegativity; by chemical properties: the amount of neutral sugars (N-acetyl-galactosamine, N-acetyl-glucosamine, galactose and glucose) in cmLSLs of patients with atherosclerosis is 1,5-2 times lower than in native lipoproteins, the levels of free and etherified cholesterol and triglycerides, monoglycerides and free fatty acids are higher, cmLDLs are oxidized and contain altered apolipoprotein B. It is also known that cmLDLs enhance proliferation of subendothelial smooth-muscle cells of the vascular intima, activating synthesis of protein by cells and components of the connective-tissue matrix, determining early clinical manifestations of atherosclerosis. The presented review summarizes the results of many-year studies of cmLDLs, carried out at the Scientific Research Institute for Atherosclerosis and the Laboratory of Angiopathology of the Scientific Research Institute of General Pathology and Pathophysiology both headed by A.N. Orekhov, and dedicated to various aspects of the effect of modified LDLs on the inner vascular wall.