Although the Japan Atherosclerosis Society guideline for the diagnosis and prevention of atherosclerosis cardiovascular diseases for the Japanese population provides targets for low-density lipoprotein (LDL) cholesterol, triglycerides, and high-density lipoprotein (HDL) cholesterol to prevent cardiovascular disease in patients with dyslipidemia, there is no guideline specifically targeting the treatment of type IIb dyslipidemia, which is one of the most common types of dyslipidemia, along with type IIa and type IV dyslipidemia. Type IIb dyslipidemia is important because it sometimes accompanies atherogenic lipid profiles, such as small, dense LDL, remnants, low HDL cholesterolemia. It is also associated with type 2 diabetes mellitus, metabolic syndrome, and chronic kidney disease (CKD), and most patients with familial combined hyperlipidemia (FCHL) show this phenotype; therefore, it is assumed that patients with type IIb dyslipidemia have a high risk for cardiovascular disease. Thus, the management of type IIb dyslipidemia is very important for the prevention of cardiovascular disease, so we have attempted to provide a guideline for the management of type IIb dyslipidemia.