A method for adjusting a zero position of a brake pedal of a brake system of a motor vehicle. A separating valve arranged at least between a main brake cylinder and the respective wheel brakes of the brake system is opened in order to reduce a volume of the brake fluid in a secondary circuit of the brake system. At least one separating valve is then closed again after the volume of the brake fluid of the secondary circuit has been reduced by the predetermined volume amount, and the brake pedal is moved to a new zero position.