The invention relates to a method for determining the rotary position of the rotor of an electric machine, which comprises star-connected phase conductors (1, 2, 3), wherein a measurement signal (M) representing the rotary position of the rotor within a magnetic half-period is determined from the potential at the star point (6). According to the invention, at a measurement time (t0) a specified voltage is applied to the ends of all the phase conductors (1, 2 3) by forcing the star point to a specific potential, at a time (t1) following the measurement time (t0) a voltage that deviates from the specified voltage is applied to the ends of one of the phase conductors (1, 2, 3), and then the measurement signal (M) is derived from the current (I) that develops from the measurement time (t0) in a connection of the star point (6) to the specified potential.