The leaves of terrestrial plants are capable of absorbing nutrients supplied in an aqueous medium. This capacity is exploited in many agronomic practices like application of herbicides, growth regulators and inorganic nutrients, for the purpose of enhancing crop production. The mechanisms of foliar absorption and subsequent transport of inorganic nutrients are discussed here. The penetration of the nutrient elements supplied to the leaf, through the outermost barrier—the cuticle—absorption by the leaf cells within, and transport from cell-to-cell finally to the conducting system of the leaf, are as complex as those following the root absorption. Yet, foliar supply of nutrients have many advantages over the root-feeding. There have been considerable interest in the practical use of this technique, as also several accomplishments not only in the understanding of the mechanisms involved in foliar uptake, but also in the development of chemicals and surfactants for the greater effectiveness.