A one-dimensional cyanide-bridged coordination polymer, poly[[aquadi-μ-cyanido-κ(4)C:N-hexacyanido-κ(6)C-(dimethylformamide-κO)bis(3,4,7,8-tetramethyl-1,10-phenanthroline-κ(2)N,N')terbium(III)molybdate(V)] 4.5-hydrate], [MoTb(CN)8(C16H16N2)2(C3H7NO)(H2O)]·4.5H2O}n, has been prepared and characterized through IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. The compound consists of one-dimensional chains in which cationic [Tb(tmphen)2(DMF)(H2O)](3+) (tmphen is 3,4,7,8-tetramethyl-1,10-phenanthroline) and anionic [Mo(V)(CN)8](3-) units are linked in an alternating fashion through bridging cyanide ligands. Neighbouring chains are connected by three types of hydrogen bonds (O-H···O, O-H···N and C-H···O) and by π-π interactions to form a three-dimensional supramolecular structure. In addition, magnetic investigations show that ferromagnetic interactions exist in the compound.