In this article, a new application of the room temperature ionic liquid, tetramethylammonium tetrafluoroborate, is described. This ionic liquid is used as a stabilizing agent and the reaction medium for the synthesis of CoFe Prussian blue analogue nanoparticles using N,N-dimethyl formamide as a complexing agent. The as-synthesized Prussian blue analogues were characterized by various techniques and were used to catalyze the reaction of epoxidation of styrene. The catalytic activity of Prussian blue analogues prepared in ionic liquid was superior to that of Prussian blue analogues prepared in aqueous solution.