Abstract: Desulfurization of hydrocarbon feeds is achieved by first contacting the entire feed with a hydrodesulfurization catalyst in a hydrodesulfurization reaction zone operating under mild conditions; a flashing column downstream of the hydrodesulfurization reaction zone fractionates the effluent to obtain a first fraction which contains refractory organosulfur compounds and a second fraction that is substantially free of organosulfur compounds, since the organosulfur compounds boiling in the range of this fraction were the labile organosulfur compounds which were initially removed by mild hydrodesulfurization. The first fraction is contacted with a gaseous oxidizing agent over an oxidation catalyst having a formula CuxZn1-xAl2O4 in a gas phase catalytic oxidation reaction zone to convert the refractory organosulfur compounds to SOx and low sulfur hydrocarbons. The by-product SOx is subsequently removed, producing a stream containing a reduced level of organosulfur compounds.