Resumen del autor, extraído del trabajo. Increased environmental awareness has resulted in a worldwide trend for transportation fuel reformulation. Gasoline parameters such as RVP, benzene, olefins and aromatics concentrations are increasingly tightened. However, gasoline sulphur is clearly becoming under increased scrutiny. FCC Gasoline contributes over 90% of the gasoline sulphur so future sulphur specifications will require over 90% desulphurisation of the FCC gasoline. With conventional hydro treating, the conditions necessary required to achieve the desired sulphur level, the octane loss through olefin hydrogenation is considerable and mercaptans formation requires further purification to produce a sweet gasoline. The knowledge of the chemical reactions occurring during FCC gasoline hydrodesulfurization (including HDS mechanism, mercaptan formation, olefin reactivity), performed under specific conditions regarding the classical HDS processes, enables to criticize conventional processes and to propose new attractive solutions. Based on these, the Prime-G process featuring the use of dedicated catalytic beds is described in this paper. Prime-G is a versatile hydrodesulfurization process, which enables to meet future gasoline sulphur specifications while providing a large operating flexibility with reference to feedstock and desired olefin saturation.