Process for the production of paraxylene from a C8 aromatic feedstock that comprises the following stages: A stage for separation by adsorption in a simulated moving bed SMB that produces an extract that contains at least 95% paraxylene and at least one raffinate R that contains ethylbenzene, A recycling of raffinate to the SMB separation stage after isomerization, in which R is separated in membrane separation means to obtain a first fraction F1 that is relatively high in ethylbenzene, which is purged, and an additional fraction F2 that is relatively low in ethylbenzene, which is recycled to the SMB after a single isomerization, preferably in the liquid phase.