The liquid-phase hydrodechlorination of chlorobenzene with molecular hydrogen was studied over palladium-supported catalysts. The reaction takes place at a gradually decreasing rate through progressive poisoning of the active phase by chloride ions. It is found that the correct choice of the metallic precursor (free of chloride ions) is crucial for the optimum performance of the final solid obtained. In addition, a better resistance to chlorine is observed when the size of the metallic particle increases. The supports tested, viz. SiO2/AlPO4, ZrO2, and MgO, significantly affected catalyst deactivation, Thus, supports that can capture chloride species (e.g., ZrO2) allow the reaction to finalise within relatively short times. The reaction appeared to be structure-sensitive in regard to the initial activity. Changing dispersion from 54 to 7% was accompanied by an increase in catalytic activity by a factor of 20.