Method (100) for operating a radar system (1) of a vehicle (2), wherein the radar system (1) has at least one radar sensor (10) for detecting at least one target (5) outside the vehicle (2), comprising the following steps: - Performing a prediction of an ego-velocity (vEgo) of the vehicle (2), so that a prediction result is determined, - Performing a classification for classifying the at least one detected target (5) as a stationary target (5a) using the prediction result, so that a classification result is determined, - Selecting one of at least two estimation methods (140) for an estimation of the ego-velocity (vEgo), wherein the selection is dependent on an evaluation of the classification result.