The reaction of Co(II) with 5,15-dipyridyl-10,20-diphenylporphyrin (H2DPyP) produces the first metal-organic coordination polymer supported by a trans meso-bifunctional porphyrin ligand. Formulated empirically as [Co-3(DPyP)(3)](.)4DMF, this compound exhibits a ribbonlike coordination network consisting of tetranuclear metalloporphyrin cages. The DMF guest molecules fill the intra-ribbon cages as well as the inter-ribbon space. Evacuation Of [COY (DPyP)(3)](.)4DMF at 130 degreesC generates [Co3(DPyP)(3)] that retains crystallinity, as shown by its powder X-ray diffraction pattern, which is consistent with that of [Co-3(DPyP)(3)](.)4DMF.