The photo-assisted catalytic degradation of tetrachloroethylene (PCE) was studied in a tubular photoreactor packed with TiO2 pellets prepared by sol-gel method. The experiments were performed in a noncirculating mode. Dichloroacetate on the catalyst surface together with phosgene and CCl4 in the gas phase were detected. The effects of operating conditions on the observed rate of reaction were investigated. Water vapor competed with PCE for the same adsorption sites on the TiO2 surface. Therefore, reaction rates decreased when the mole fraction of H2O was 50-60 times higher than that of PCE. Reaction temperature and space time play key roles in the degradation Of PCE to CO2. Under the best of our experimental conditions, 80% of the initial PCE could be completely mineralized.