Abstract: A brake system for motor vehicles comprising a brake master cylinder which can be activated by means of a brake pedal and to which wheel brakes are connected. The brake system also comprises an electrically controllable pressure-generating device, a pressure-regulating valve arrangement to regulate a wheel brake pressure set at a wheel brake, a first electronic control and regulating unit which controls at least one of the pressure-generating device, the pressure-regulating valve arrangement, and an electrically controllable auxiliary pressure-generating device by means of which the brake master cylinder can be activated by means of which a pressure in an intermediate chamber of the brake master cylinder can be controlled or regulated.