A hydraulic system for utility vehicles is disclosed for prioritized pressure medium supply to internal and external pressure medium consumers (6, 11, 12), which are fed via load sensing spool valves (20, 26), the external pressure medium consumers (11, 12) being supplied with pressure medium via a priority valve (17). In order to improve the work quality of an implement driven by an external pressure medium consumer, the present invention provides that priority can be selectively assigned to the internal (6) or the external (11, 12) pressure medium consumers. It is thus possible for the driver, in order to ensure optimum operation of the utility vehicle in critical situations, to give priority to external pressure medium consumers. In this way during operation of an implement for dispersion of substances, better work quality can be attained, as a reduced supply and thus slower function of the internal power lift are accepted.