The metabolic syndrome increases the risk of many diseases. There are many investigations on the role and alterations of High-Density Lipoprotein (HDL)-cholesterol in different diseases. HDL-cholesterol is an important component of metabolic syndrome. Low HDL-cholesterol has been shown among subjects with metabolic syndrome. Low levels of HDL-cholesterol are collaborated with elevated risk of cardiovascular disease, coronary heart disease, myocardial infarction, stoke and Alzheimer disease. The increased prevalence of metabolic syndrome and its relation with low levels of HDL-cholesterol accentuate its diagnostic importance and medical care. The aim of present study was to review HDL-cholesterol alterations in metabolic syndrome.