Current consumption levels of oat products are low. However, oats are a nutritious foodstuff, supplying protein of relatively good quality and significant quantities of vitamins and minerals. As a bland and nutritious foodstuff, oats are valuable for the nutrition of infants and the sustenance of adults. Oats are generally consumed as oatmeal or rolled oats, but oat bran has become available in recent years. In addition to their nutritional attributes, dietary oat products exert a number of physiological effects that may be beneficial in the prevention or amelioration of pathophysiological states, including improvements in gastro-intestinal function, modulation of glucose metabolism, and decreasing blood cholesterol status. The latter effects have attracted considerable attention and a critical review of the data indicates that dietary oats have the ability to lower blood cholesterol and that they are most effective at high dose levels in hypercholesterolaemic individuals. Although the soluble fibre, beta-glucan gum appears to be the major hypocholesterolaemic agent, its mode of action is not fully understood.