A critical review is presented of the enthalpies of the thermal dissociation (DELTAH(d)) and formation (DELTAH(f)) available in the literature, as well as the crystal lattice energies (E(c)) for inorganic and organic hexahalogenozirconates M2I(or M(II))ZrX6, where M(I) and M(II) denote monovalent and divalent cations respectively, and X denotes a halogen. The enthalpies of formation of the salts were determined from known DELTAH(d) values and the enthalpies of formation of the decomposition products of hexahalogenozirconates, taken from the literature. The combination of the values of the enthalpies of formation of hexahalogenozirconates thus evaluated, and those of the literature, with the literature values of the enthalpy of formation of cations and the theoretically determined enthalpies of formation of ZrX62- (or the electrostatic lattice energies of the salts) has afforded lattice energies of the salts (or enthalpies of formation of gaseous ZrX62-). Values of DELTAH(f) were also assessed, taking theoretically determined electrostatic lattice energies of the salts and enthalpies of formation of ZrX62-, and literature or theoretically determined values of the enthalpy of formation of gaseoUs cations. Finally, the lattice energetics was examined following the Kapustinskii-Yatsimirskii approach which enabled an independent set of crystal lattice energies and thermochemical radii for ZrX62- and complex cations to be obtained. The various thermochemical quantities correlate with each other reasonably well, thus increasing their reliability.