The centrosymmetric dinuclear title compound, [Zn(2)Cl(4)(C(4)H(12)N(2))(2)], is isostructural with its previously reported Cu(II) analogue [Phelps, Goodman & Hodgson (1976 ▶). Inorg. Chem.15, 2266-2270]. In the title compound, each of the Zn(II) ions is coordinated by two N atoms from a chelating N,N-dimethyl-ethylenediamine ligand, two bridging Cl atoms and one terminal Cl atom. The coordination environment is distorted square-pyramidal. The Zn-Cl bond distances of the two bridging Cl atoms are distinctly different: the equatorial Cl atom exbibits a Zn-Cl distance of 2.318 (1) Å and the axial Cl atom exbibits a Zn-Cl distance of 2.747 (2) Å, which is significantly longer. The mol-ecule can thus be seen as a dimer of two nearly square-planar monomeric units which are related to each other by an inversion center located in the middle of the dimer. Within one monomeric unit, the Zn atom, the two N atoms and the two Cl atoms are almost coplanar, with a mean deviation of only 0.05 (1) Å from the associated least-squares plane. The Zn⋯Zn distance within the dimer is 3.472 (3) Å. N-H⋯Cl and C-H⋯Cl hydrogen-bond inter-actions connect neighboring mol-ecules with each other.