Although barley has traditionally been one of the most important food grains, the intake in Japan has been decreasing during the last forty years. Barley provides many essential nutrients (carbohydrates, dietary fiber, vitamins and minerals) and functional components (dietary fiber and polyphenol). Studies on the health benefits of barley have been rapidly increasing in terms of the cholesterol-lowering effect, serum glucose and insulin normalization, decreased body fat accumulation, and blood pressure reduction. It has been scientifically proven that the soluble dietary fiber in barley, β-glucan, might reduce the risk of cardiovascular disease (CVD). It is inferred that two principal mechanisms may contribute to the cholesterol-lowering effects of barley and β-glucan: 1) reduction of cholesterol and bile acid absorption from the small intestine, 2) inhibition of cholesterol synthesis in the liver. Barley and β-glucan have therefore been approved as a potential health benefit against the risk of CVD in the United States and Sweden. Recent clinical studies have suggested that the consumption of barley and its products might reduce many risk factors associated with the metabolic syndrome, namely diabetes, hypertension and dislipidemia. This review presents information that will hopefully increase the awareness of professionals and consumers for the health benefits of barley.