A side pincushion correcting circuit is provided in a color television receiver of the type including a cathode ray tube having an index stripe disposed on a screen scanned by a cathode beam and a detector for detecting the scanning of the index stripe by the cathode beam and producing a pulse signal as a result of such detecting. The side pincushion correcting circuit comprises a pulse forming circuit for generating a reference signal in correspondence to the pulse signal from the detector, a phase comparator for comparing the phase of the reference signal to that of a control pulse, such as the horizontal flyback pulse, associated with the commencement of scanning in the horizontal direction, and providing an output signal whose magnitude is proportional to the phase difference between the reference signal and the control pulse, and a horizontal deflection circuit supplied with the output signal from the phase comparator for controlling the scanning of the cathode beam in the sense to correct for side pincushion distortion.