In a fuel injection system for an internal combustion engine, in which the fuel pumped by means of a high-pressure pump can be injected into the combustion chamber of the engine at at least two different, high fuel pressure via injectors, between the high-pressure pump and the injectors, at least one central pressure booster unit for all the injectors is provided. The pressure booster unit is triggerable in a targeted way as need, and as a result the fuel which is at the higher pressure can be better regulated in quantity, and the losses from friction can be reduced accordingly as well.