A simple, rapid, and highly efficient method has been developed for the aza-Michael addition of acrylonitrile to 2-aryl-oxymethylbenzimidazole derivatives in the presence of anhydrous potassium carbonate under microwave irradiation. A series novel of 1-cyanoethyl-2-aryloxymethylbenzimidazole derivatives have been prepared and characterised by 1H NMR, 13C NMR, IR spectra and elemental analysis.