Owing to the presence of crystallographic twofold rotation axes (site symmetry 2, Wyckoff letters e and f), the asymmetric unit of the title compound, [Mn(C(12)H(8)N(5))(CHO(2))](n), contains one-half of an Mn(II) cation, one-half of a bpt anion (Hbpt is 3,5-di-2-pyridyl-4H-1,2,4-triazole) and one-half of a formate anion. The bpt and formate ligands occupy the same C(2) symmetry, while the Mn(II) ion resides on another crystallographic twofold rotation axis. Each bpt ligand acts as a cis-bis-chelate to ligate two Mn(II) ions into a one-dimensional chain running along the crystallographic 4(1) screw axis. Adjacent Mn(II) ions are further bridged by a μ(2)-formate ligand, completing the distorted octa-hedral coordination geometry of the cation.