Caking of ammonium nitrate is prevented by coating the finished product with inert dust and/or a surfactant and by adding an inorganic salt or nucleating agent (a stabilizer) to the melt prior to prilling. In the present work, selected locally available anticaking agents are tested on ammonium nitrate produced in Egyptian fertilizer companies. Anticaking efficiencies are evaluated and compared. Optimum doses for each anticaking agent and anticaking composition are determined by a bench scale experimental technique.