More and more functional foods or nutraceuticals have proved to be important allies both to health promotion and disease treatment. For these reasons many research has been going on aimed at identifying functional components in foods and relate them with positive physiological effects. Although there is a distinction between what is a functional food and a nutraceutical, the truth is that these two concepts are much related. In fact, both nutraceuticals and functional foods are foods, or dietary components, that provide some health benefit beyond basic nutrition. However, while functional foods aim at providing some health benefit in general, the nutraceuticals go further beyond, and include aspects such as the effective prevention or treatment of disease. Recent research continues to support many findings that seem to validate the benefits of foods or food components to the promotion of health. It has been widely stated that people who consume a wide variety of foods containing some bioactive molecules like carotenoids, fibers, flavonoids, fatty acids, phytoestrogens, vitamins and minerals, among others, show a reduced risk of developing some diseases and tend to have a better health. As an example, the use of antioxidants provides protection against harmful free radicals, usually associated with cardiovascular disease, cancer, diabetes, Alzheimer’s dis- ease and age-related functional decline. Also the ingestion of dietary fibres has been related to improvement in gastroin- testinal functions, as well as a reduced risk of developing colorectal cancer. The present work gives a general overview of functional foods, pointing out examples of some foods with a recognized functional ability, as well as leaving some clues about new developments in this field.