A process for presulfiding a plurality of sorbent particles prior to using at least a portion of the particles to at least partially desulfurize a hydrocarbon feed stream. Typically, presulfiding can be carried out in a presulfiding zone under presulfiding conditions. In one embodiment, the process can be carried out in a desulfurization system comprising a fluidized bed reactor and fluidized bed regenerator and can be completed in less than about 36 hours.