A method for unambiguous determination of a range to and/or of a relative velocity of an object with respect to a motor vehicle is disclosed. An unambiguity area (RUn) for the range and/or an unambiguity area (VUn) for the relative velocity may be determined by means of a frequency-modulation continuous-wave radar in the motor vehicle, with a predetermined sequence of frequency-modulated signal pulses being transmitted by the frequency-modulation continuous-wave radar in a measurement cycle. Mutually different unambiguity areas (RUn) for the range and/or mutually different unambiguity areas (VUn) for the relative velocity are defined for at least two successive measurement cycles, and the range and/or the relative velocity are/is determined on the basis of, in each case, at least one measured value for the range and/or for the relative velocity from each measurement cycle.