A radar sensor for driver assistance systems in motor vehicles includes a transmitting and receiving device for transmitting and receiving radar signals, an electronic evaluation device for evaluating the received signals, an electronic control device for controlling the operating functions of the radar sensor, and a self-monitoring device for detecting operating parameters of the radar sensor and for comparing the detected parameters to specific setpoint values, where a control device modifies at least one of the operating parameters and a control circuit controls the parameter to the setpoint value thereof.