3-(1-Acylaminooctadecyl)indole-2-carboxylic acids and 3-(1-acylaminooctadecyl)-1-methylindole-2-carboxylic acids were designed and synthesized as inhibitors of cytosolic phospholipase A2. Enzyme inhibition was assayed by evaluation of calcium ionophore A23187-induced arachidonic acid release from bovine platelets. While compounds with 1-octadecanoylaminooctadecyl groups in position 3 of the indole were inactive inhibition data for 3-[1-(3-phenylpropionylamino)octadecyl]indole-2-carboxylic acids could not be evaluated because of lysis of the platelets. However 3-(octadecanoylaminomethyl)indole-2-carboxylic acid derivatives and 1-methyl-3-octadecanoylindole-2-carboxylic acid proved to be inhibitors of cytosolic phospholipase A2. The most active inhibitor was the latter compound with an IC50 of 8 microM.