The title compound, [Mn(2)(HO(3)PCH(2)CH(2)COO)(2)(C(8)H(8)N(2))(2)(H(2)O)(2)], was obtained by hydro-thermal synthesis. The manganese(II) ions are six-coordinate and are linked by two 2-carboxy-ethyl-phospho-nate ligands, forming a centrosymmetric dimer. The Mn ions adopts a distorted octahedral coordination geometry. The dimers are further linked by O-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distance 4.2754 (4) Å].