This work reports an adapted route to the highly efficient synthesis of arylidene ethyl cyanoacetate derivatives in the presence of catalytic amounts of molybdenum oxide nanoparticles (MoO₃ NPs) under green conditions at ambient temperature. From the reaction, a wide range of novel arylidene ethyl cyanoacetates was successfully synthesized with high yields from the Knoevenagel condensation reaction between various aryl aldehydes and ethyl cyanoacetate in the presence of MoO₃ nanoparticles. The capability of catalyst to separate from the reaction mixture and then reuse is another advantage of this reaction. Furthermore, obtained products belong to analogous of organic compounds that have shown biological activity, and can be used pharmaceutics.