Abstract: A feed-dispersion system for hydrocarbon feeds of fluid catalytic cracking units is described, which comprises: a feed-injection system made up of two concentric conduits, where the atomization fluid flows through the inner conduit, while the liquid feed flows through the annular space formed by the outer surface of the inner conduit and the inner surface of the outer conduit; an atomization unit having nozzles arranged in rows, with one row having central nozzles connected to the inner conduit for atomization fluid, and two or more rows of side nozzles, connected to the outer feed conduit, the central nozzles and side nozzles of the atomization unit being geometrically placed so that the energy of the atomization fluid is fully transferred by contact to the flow of feed, this resulting in the complete atomization of the feed; a mixing chamber formed by the edges of the central nozzles, the dimensions of which are able to prevent the coalescence of the formed oil droplets.