Organic polymeric networks (OPNWs) containing the repeated structural units of α-aminonitriles were successfully prepared for the first time in high yields (88–93%) via one-pot Strecker reactions of dialdehydes, di/tri-amines, and trimethylsilyl cyanide under catalyst-free conditions. The OPNWs possessing two functional groups (cyano- and secondary amino-groups) were very stable and insoluble in water and many common organic solvents, and also had high thermal stabilities.