In the title compound, [Mn(CHO(2))(2)(C(12)H(10)N(4))(2)](n), the Mn(II) atom and the benzene ring of the ligand lie on an inversion centers. The Mn(II) atom has an octa-hedral coordination environment composed of four N atoms from two different symmetry-related N-heterocyclic ligands forming the basal plane, and two O atoms from symmetry-related formate anions occupying the apical positions. The title compound forms a two-dimensional (4,4) net parallel to (100) with all the Mn(II) atoms lying on a plane. The crystal structure is consolidated by inter-molecular N-H⋯O hydrogen bonds..