Three interpenetrating Co(II)/Ni(II) coordination polymers, [Co(pytpy)(sfdb)]n (1), [Co2(pytpy)(sfdb)2]n (2) and [Ni(pytpy)(sfdb)]n·nH2O (3) (pytpy = 4'-(4-pyridyl)-4,2':6′,4″-terpyridine, H2sfdb = 4,4′-sulfonyldibenzoic acid) have been hydrothermally synthesized and structurally characterized. They all feature interpenetrating 3D honeycomb networks. Compound 1 is a 4-fold 3D polymeric structure, bidentate-bridging pytpy ligands join the square wave-like chains based on Co(II) centers and μ2-sfdb2- linkers to form the final 3D honeycomb network. Compound 2 is also a 3D honeycomb structure, which features 2-fold interpenetrating structure with unusual paddle-wheel secondary building units (SBUs). The topological net of compound 3 is identical to 1, but the central metal and its coordination environment are different from those of compound 1. In addition, diffuse reflectance UV–vis spectroscopic measurements and thermal gravimetry analyses have been used to characterize these compounds.