The anomeric effect is an important aspect of the stereochemistry of natural products. This text provides a review of the structural, conformational and chemical manifestations of the anomeric effect. It examines the historical aspects and general consequences of the stereoelectronic interactions as well as areas of new developments, such as: the differentiation of the endo- and exo- anomeric interactions; the specific analysis of enthalpic component of anomeric effects; the critical evaluation of the kinetic and reverse anomeric effects and lower-row anomeric segments.