Abstract: Catalysts for the isomerization of hydrocarbons, particularly normal paraffins having from 4 to 7 carbon atoms, as well as a process for the preparation of the catalyst and a process for their use in the isomerization of such hydrocarbons are disclosed.The catalysts are composed of a zeolite support impregnated with a mixture of zirconium, a refractory metallic oxide and at least one platinum-group metal.The process for the preparation of the catalysts involves steps of depositing the zirconium, on the zeolite support, mixing (zeolite+Zr) with alumina, and depositing a platinum group metal on the mixture (zeolite+Zr)/alumina, accompanied by intermediate calcining and shaping steps, and followed by drying and final calcining steps. Alternative methods for depositing the zirconium and platinum group metals on the zeolite are disclosed.