In a method for automatic determination of the actual speed interval of a flowing medium in flow measurements in magnetic resonance imaging, an overview image (localizer) is acquired displayed on a screen, a scout flow measurement is performed by acquiring an image series during a motion cycle at a pre-determined speed interval in a tissue-area to be measured, the peak speed of the medium in the tissue area to be measured is determined on the basis of the scout flow measurement, an optimized flow measurement is performed by acquiring the same images from the acquired image series on the basis of the determined peak speed, and the speed-resolved tissue area obtained by means of the optimized flow measurement is displayed on the screen.