A method for warning a driver when parking a motor vehicle, in which an inclination variable describing the roadway inclination in the longitudinal direction of the vehicle is ascertained, a vehicle standstill is ascertained, a steering angle variable describing the steering angle is ascertained, and in the case of a standstill of the vehicle a driver warning information is output if the inclination variable fulfills a specified inclination condition and the steering angle variable fulfills a specified steering angle condition.