A driver assistance system for motor vehicle/trailer combinations having a towing vehicle and at least one trailer, having a sensor unit for detecting the dynamics of the trailer, an electronic analysis unit for analyzing the data of the sensor unit, and an output unit for outputting an instability signal, which indicates a dynamic instability of the trailer established by the analysis unit, and having at least one assistance function which automatically triggers and controls a braking operation under specific conditions, the assistance function being designed to limit the absolute value of the deceleration of the vehicle during the braking operation to a value as a function of the instability signal.