The invention relates to a device and a method for determining the rotational position of the rotor of an electric machine that has star-connected pole winding phases. The device is equipped with a unit for applying voltage pulses (14-16) to at least one of the phases (1-3) and a unit that evaluates the neutral point potentials generated by the voltage pulses (14-16). The invention is characterized by the provision of the aforementioned unit for applying time-delayed voltage pulses (14-16) to different phases (1-3) and the unit for producing at least one differential between the neutral point potentials generated by said voltage pulses.