Background: Currently, there is no unified treatment algorithm of cardiac autonomic neuropathy (CAN) in patients with type 2 diabetes mellitus (T2DM). The aim of this study was to investigate the effects of simvastatin (SIM) and ω-3 polyunsaturated fatty acids (ω-3 PUFAs) on blood lipid profile and insulin resistance (IR) in patients with T2DM and definite CAN. Methods: The study involved 72 patients with T2DM and definite CAN. Patients were divided into four groups: 1st -received standard hypoglycemic therapycontrol (n = 15); 2nd (n = 22) -in addition SIM 20 mg/q.d.; 3rd (n = 18) -in addition 1 capsule/q.d. of the ω-3 PUFAs; 4th (n = 17) -in addition SIM 10 mg/ q.d and 1 capsule/q.d of the ω-3 PUFAs for three months. The concentration of glucose, glycated hemoglobin A1c, immunoreactive insulin (IRI), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG) in the blood were determined. Homeostasis model assessment IR (HOMA-IR), atherogenic coefficient (AC), TG/LDL-C, TG/TC, TG/LDL-C and TG glucose (TyG) were calculated.