The title polymeric compound, [Mn(2)(C(10)H(2)O(8))(C(12)H(8)N(2))(2)](n), was obtained by the reaction of manganese(II) chloride tetra-hydrate with benzene-1,2,4,5-tetra-carboxylic acid (H(4)bta) in aqueous solution. Each Mn(2+) ion is coordinated in a distorted octa-hedral geometry by two N atoms from one 1,10-phenanthroline ligand and four O atoms [Mn-O = 2.116 (2)-2.237 (2) Å] from three bta(4-) ligands, which also act as bridging groups between the Mn(2+) ions.