The invention relates to a method for determining the position (ΘR) and the rotational speed (nR) of a rotor of an electrical machine during an active short circuit and a rotor-state determining device (10) designed to carry out the method. The method comprises the steps of determining the short circuit currents (Iu, Iv, Iw) resulting during the short circuit, determining a total current (Iα, Iβ) resulting from the short circuit currents (Iu, Iv, Iw), determining a stator current angle (ψI) of the total current (Iα, Iβ) with respect to a stator coordinate system (α, β), determining a rotor current angle (φI) of the total current (Iα, Iβ) with respect to a flux direction (dR) of the rotor, this step comprising the steps of calculating an amount variable (I) of the total current (Iα, Iβ), determining the rotor current angle (φI) on the basis of a characteristic dependence between the amount variable (I) and a rotor current angle (φI), which dependence is created for the electrical machine, the rotor position (ΘR) corresponding to a sum of the stator current angle (ψI) and the rotor current angle (φI), and the rotor rotational speed (nR) resulting from monitoring of the rotor position (ΘR).