Phospholipases A₂ are involved in inflammatory processes such as the liberation of free arachidonic acid from the membrane pool for the biosynthesis of eicosanoids. Inhibitors of these enzymes are proving useful in determining the biological roles of phospholipases A₂ in complex cellular processes and may also have therapeutic potential. Inhibition of these lipolytic enzymes is more difficult to characterize as the enzymatic reaction occurs at a lipid/water interface. This review focuses on the description of a number of classes of rationally designed phospholipase A₂ inhibitors. The development of a theoretical framework for the proper analysis of inhibitors is presented. Structural studies of phospholipase A₂‐inhibitor complexes suggest how the lipolysis reaction is catalyzed. Finally, some recent results on the use of phospholipase A₂ inhibitors in living cells and tissues are revealed.— Gelb, M. H., Jain, M. K., Berg, O. G. Inhibition of phospholipase A₂. FASEB J. 8: 916‐924; 1994.