Tetrachloromethane (TCM) has been decomposed under methane oxidation conditions on calcium hydroxyapatite (CaHAp). Although TCM is stable at 773 K in the absence of a catalyst, it is completely decomposed at the same temperature in the presence of CaHAp. The preponderance of the chlorine resulting from the decomposition appears as methyl chloride and hydrogen chloride with the remainder trapped in CaHAp. During the decomposition the CaHAp was initially converted to calcium chlorapatite and ultimately to calcium chloride with concomitant changes in the selectivities but not the conversion of TCM. The decomposition of TCM is strongly influenced by the PO4 groups and the oxidation of methane by the OH groups in CaHAp.