A heterobimetallic cyano-bridged 1D coordination polymer of the composition [Ni(baepn)(l-NC)Fe(CN) 3 -(NO)(l-CN)] n Á3H 2 O has been synthesized by the reaction of nickel(II) nitrate hexahydrate, baepn (baepn = N, N 0 -bis(2-aminoethyl)-1,3-propanediamine), and sodium nitroprusside dihydrate in a methanol-water mixture. The complex was characterized by physicochemical and spectroscopic methods. The crystal structure was established by singlecrystal X-ray diffraction analysis. It reveals cyano-bridged heterometallic chains consisting of alternating arrays of Ni(II) and Fe(II) atoms, both being embedded in distorted octahedral environments. Low-temperature susceptibility measurements show the presence of weak antiferromagnetic exchange interactions between paramagnetic Ni(II) centers (J = -0.46 cm -1 ) through long diamagnetic [Fe(CN) 5 -(NO)] 2-bridges. Spin state of the iron atom was established by 57 Fe Mössbauer spectroscopy.