Whole grain barley has been widely recognized as a valuable source of a number of biologically active compounds with unique health benefits. The great number of bioactive nutrients and their pleiotropic physiological effects make barley an ideal grain, raw material, and ingredient for the development of functional foods. This chapter discusses key issues and challenges currently faced by barley growers and manufacturers in producing high-quality products. It also reviews the known and potential bioactive compounds in barley, as well as research that has been carried out on barley and its health benefits. It concludes by discussing research that examines potential influences of barley bioactivity, future trends in research for barley and also highlights several sources for further information.