In the title compound, {[Zn(C(4)H(4)O(6))(H(2)O)]·2H(2)O}(n), the l-tartrate ligands adopt μ(4)- and μ(2)-coordination modes. The Zn(II) atom adopts an octa-hedral geometry and is chelated by two kinds of l-tartrate ligands through the hydr-oxy and carboxyl-ate groups and coordinated by one unchelating carboxyl-ate O atom and one water mol-ecule. In the crystal, the l-tartrate ligands link the Zn(II) atoms, forming a two-dimensional coordination layer; these layers are futher linked into a three-dimensional supra-molecular network by O-H⋯O hydrogen bonds between the two-dimensional coordin-ation layers and the uncoordinated water mol-ecules. The latter are equally disordered over two positions.