The synthesis of various alpha-aminonitriles, precursors of alpha-amino acids has been carried out in moderate to high yields and high purity by the Strecker reaction from ketones, aliphatic/aromatic amines and TMSCN using a new "green" Lewis acid catalyst, Nafion-Fe (iron Nafionate, Fe(III) salt of Nafion-H, a solid polymeric perfluoroalkanesulfonic acid) under conventional thermal as well as microwave conditions. Microwave and solvent-free conditions applied in this method shorten the reaction times, improve the yields and diminishes the formation of side products. Strecker reaction occurs smoothly with secondary aliphatic amines also under these conditions which is not common under conventional conditions.