The title framework compound, [Mg(3)(C(8)H(4)O(4))(3)(C(3)H(7)NO)(4)](n) or [Mg(3)(bdc)(3)(DMF)(4)](n), was obtained as a side product of the solvothermal reaction of magnesium nitrate, terephthalic acid (bdcH(2)), and 1,3-bis-(4-pyrid-yl)propane in a 1:2:1 ratio in dimethyl-formamide (DMF). The asymmetric unit consists of three Mg(II) cations, three terephthalate anions, and four coordinating DMF mol-ecules. One of the four DMF mol-ecules was refined as disordered over two mutually exclusive positions, with an occupancy rate for the major moiety of 0.923 (4). The three Mg(II) cations possess distorted octa-hedral coordination geometries that form linear Mg trimers. Of the three Mg(II) cations, the central Mg(II) is octa-hedrally coordinated by six different carboxyl-ate O atoms. The terminal Mg(II) cations are bonded to four O atoms of three bdc linkers and to two O atoms of coordinating DMF mol-ecules. The compound has a two-dimensional 3(6)-network structure parallel to (001) that is formed by connection of the Mg trimers as distorted octa-hedral nodes to the bdc ligands as linkers.