An exterior mirror sensor system for commercial vehicles comprising an exterior mirror, a sensor for monitoring an exterior mirror zone, and an indicator for indicating objects detected in the exterior mirror zone. The sensor may be a distance sensor, a motion sensor or a heat sensor. The system may further comprise a control unit connected to the sensor and indicator for controlling the indicator. The system may further comprise a camera for recording objects in the exterior mirror zone. The control unit may actuate the indicator upon the detection of an object by the sensor. The indicator may comprise an audible indicator. The system may further comprise a data input unit for recording data detected by the sensor wherein the data input unit is connected to the control unit and receives the data detected by the sensor from the control unit.