The three-dimensional coordination polymer [Cd(tcm)(hmt)(H2O)](tcm) (tcm(-) = tricyanomethanide, C(CN)(3)(-); hmt = hexamethylenetetramine) has a rutilelike topology, with octahedral centers (cadmium atoms) and trigonal centers (hmt ligands and half the tcm anions) in the ratio 1:2. One of the connections of the three-connecting hmt ligands is a hydrogen-bonding interaction with coordinated water ligands.