3-D manganese(II) coordination polymers bis(nico-tinato)manganese, 1, and bis[4-(3-pyridyl)ethynylben-zoato]manganese, 2, were synthesized under hydro(solvo)thermal conditions. Compounds 1 and 2 exhibit remarkably similar network topologies probably as a result of the same bent configurations and rigid structures of the m-pyridinecarboxylate ligands. Magnetic measurements of 1 and 2 indicate dominant antiferromagnetic interactions along the carboxylate-bridged Mn(II)-Mn(II) chains, and they represent new examples of one-dimensional Heisenberg antiferromagnetic chains.