The solid state reactions of tellurium oxide with zirconium and hafnium oxides were investigated employing thermogravimetry (TG), differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. The only compounds reported in these two pseudo-binary systems are ZrTe3O8 and HfTe3O8, respectively. From the results obtained in these studies it is concluded that these compounds can be synthesized in the solid state in the pure form from their binary component oxides by heating the stoichiometric mixtures to temperatures as low as 900 to 950 K where the vaporization of the more volatile component TeO2, is insignificant.