The importance of magnesium intake in relation to the metabolic syndrome has been increasingly recognized. Magnesium is an essential mineral, critical for a number of metabolic functions in the human body. The major dietary sources of magnesium intake include whole grains, legumes, nuts, and green leafy vegetables. Animal studies indicate a pivotal role of magnesium in glucose homeostasis and insulin secretion and action. Experimental and clinical studies suggest that magnesium intake may be inversely related to the risk of hypertension and type 2 diabetes mellitus, and may decrease blood triglyceride and increase high-density lipoprotein cholesterol levels. The purpose of this brief review is to summarize the epidemiologic data relating magnesium to the metabolic syndrome and to discuss the potential mechanisms.