A method for detecting rotating stall in a compressor is disclosed herein. The method comprises measuring radial vibration of the rotor relative to the stator and generating a vibration measurement signal, calculating a frequency spectrum of the vibration measurement signal, identifying a plurality of frequency bandwidths of the frequency spectrum, neglecting one first frequency bandwidth of the plurality of frequency bandwidths if the rotation frequency of the rotor falls within the first frequency bandwidth, neglecting at least one second frequency bandwidth of the plurality of frequency bandwidths if the rotation frequency of the rotor falls below the second frequency bandwidth, determining the maximum magnitude of the spectrum in each of the non-neglected frequency bandwidths, and comparing each determined maximum magnitude and a predetermined value. Rotating stall is considered occurring if at least one of the comparisons shows that the corresponding determined maximum magnitude is greater than the predetermined value.