Thermogravimetric and differential thermal analyses of Cd(OH)2, CdOHCl, and CdOHF are reported and discussed. The results show that the presence of a halogen substituent contributes to greater thermal stability of the hydroxy compound. The thermal stability increases in the order Cd(OH)2 < CdOHF ≤ CdOHCl, which is in contrast with the order of the zinc derivatives.The expected increase in the stability of the cadmium hydroxy compounds relative to the zinc hydroxy compounds was observed except for CdOHF. The exception of CdOHF is ascribed to its departure from the expected hexagonal structure and its existence in the orthorhombic form.The cadmium hydroxy compounds decompose via dehydration in the initial step, followed by hydrolysis and (or) volatilization of the cadmium halide to yield an ultimate residue of cadmium oxide.