Abstract: A process for the dehalogenation of halogen-containing aromatic compounds takes place in the vapor phase, at a temperature of between 280.degree. and 420.degree. C., by the action of hydrogen in the presence of a controlled-action hydrogenation catalyst deposited on an alumina-based support wherein the support used is modified, at least on the surface, by the incorporation of a metal in the form of a salt or an oxide, this incorporation consisting in treating the support with the said metal salt or metal oxide and then carrying out a calcination at a temperature ranging from about 500.degree. to 1,000.degree. C.