A method is provided for operating a radar system of a vehicle. The radar system has at least one radar sensor for detecting at least one target outside the vehicle. A prediction of an ego-velocity (vEgo) of the vehicle is performed, so that a prediction result is determined. A classification for classifying the at least one detected target as a stationary target is then performed using the prediction result, so that a classification result is determined. One of at least two estimation methods is then selected for an estimation of the ego-velocity (vEgo), such that the selection is dependent on an evaluation of the classification result.