Coordination complexes between α-cyanoacetamide as ligand and the group (IV) halides as Lewis acids have been prepared. In all these compounds the ligand has been found to be a bidentate, coordinating to two different metal atoms. The infrared results indicate coordination through the nitrogen of the cyano group and one of the donor atoms of the amide group, probably nitrogen. Some physical properties of the complexes strongly suggest that they are coordination polymers.