The title compound, [Zr(6)(OH)(4)O(4)(N(2)H(3)COO)(12)] · 14H(2)O, was prepared with a novel multi-step synthetic pathway. The structure contains a Zr(6)(µ(3)-OH)(4)(µ(3)-O(4))(12+) core on which twelve hydrazine carboxylate anions are bound to form neutral coordination molecules. The coordination mode of carboxylate ligand is exclusively N,O-bidentate chelating, which is observed for the first time in this class of compounds. The title compound is also the first example of isolated Zr(IV) oxo clusters with cubic symmetry. The structure is stabilized with an extensive hydrogen bond network between coordination and water molecules, and amongst the solvent water molecules themselves. Thermogravimetric studies have shown that the prepared [Zr(6)(OH)(4)O(4)(N(2)H(3)COO)(12)] · (14)H(2)O decomposed in several consecutive steps characterized by evolution of H(2)O, CO, CO(2), N(2) and H(2), finally yielding ZrO(2). The decomposition mechanism is rather complex and includes the formation of a series of amorphous intermediates.