A brake unit for motor vehicles with electric drive with a hydraulic pressure transducer and hydraulic friction brakes to increase the brake effect applied by the electric drive motor. The cooperation of the electric drive motor with the hydraulic friction brakes is controlled by an electronic controller. To increase the reliability of operation of the brake unit by making possible the buildup of hydraulic pressure in the friction brakes associated with the driven axle in the case of a failure of the electronic controller or of the entire electric system of the vehicle, the pressure transducer is arranged as a two-circuit main brake cylinder, to the first pressure space of which the friction brakes acting on the nondriven axle, and to the second pressure space of which the friction brakes acting on the driven axle are connected, wherein the connection between the second pressure space and the friction brakes acting on the driven axle is by at least one shut-off valve, which can be switched over electrically and is open in the currentless state.