During the past decade, there has been vast expansion in the research of fructooligosaccharides (FOS), including their chemistry, biochemistry, and enzymology in living organisms, as well as nutritional and health benefits. However, in spite of these considerable advances in FOS science, many other aspects of the mechanisms of FOS behind their involvement in well being have not been fully understood. FOS constitute the major part of the dry matter of edible Alliums, and the knowledge of the mechanisms of their mode of action in human metabolism are of great interest. Important progress has been made in the chemical, nutritional and clinical research areas of Alliums FOS, as well as on other FOS, and in addition to their role as quality attribute, FOS participate in other processes. This paper aims to review the occurrence, chemistry and health benefits of Alliums FOS including nutritional contribution of FOS in health and well being.