A wheel hub drive system with an electric motor that can be arranged inside a wheel rim, whereby the electric motor is formed by rotor that is at least indirectly joined to a wheel hub and by means of a stationary stator that can be supplied with alternating current. With an eye towards obtaining more space for the vehicle occupants, it is proposed to arrange the converter with its entire power electronics unit on the stator so that the wheel hub drive system can be operated with direct current from the battery of the vehicle, or else no alternating current lines have to be laid in the vehicle. Consequently, the alternating current is generated by the converter that is arranged in a converter housing attached axially next to the stator.