In the title compound, {[Mn(6)(C(8)H(4)O(4))(6)(C(4)H(9)NO)(8)]·H(2)O}(n), two of the Mn atoms are six-coordinated by six O atoms from three benzene-1,4-dicarboxyl-ate (bdc) ligands and two trans DMA (dimethyl-acetamide) mol-ecules, whereas two other Mn atoms, located on inversion centers, are both in octa-hedral coordinations by six bdc O atoms. The discrete trinuclear manganese secondary building units (SBU) of Mn(3)(O(2)CR)(6) ({-Mn-Mn-Mn-}) are linked through bdc ligands, forming a chain, while the discrete trinuclear SBU of {-Mn-Mn-Mn-} are bridged, forming another chain]. The two types of chains are linked through bdc ligands, resulting in the formation of a layer with 3(6) topology. Weak O-H⋯O and O-H⋯N hydrogen-bonding inter-actions involving the disordered water molecule (half-occupation) extend the two-dimensional layers into a three-dimensional supra-molecular framework.