The invention relates to a method for operating a parking assistance system for a vehicle, comprising at least one distance sensor that detects at least sections of the lateral immediate vicinity of the vehicle and at least one path sensor that detects the path travelled by the vehicle. According to the method, a control device determines the length and/or width of a parking space from the values measured by the sensors as the vehicle drives past said parking space. The invention is characterised in that the measured length and/or width of the parking space is/are corrected by a correction value and/or that depending on the speed of the vehicle as it drives past the parking space, the measurement is taken by means of the distance sensor at different time intervals.