The present invention relates to a method for determining the fertility of spermatozoa, said method comprising determining the total content of Vimentin variant 3 (Vim3) per spermatozoon and/or the spatial localization of the Vim3 in the spermatozoa, wherein a decreased amount of total content and/or decreased amount of (or even missing) accumulation of Vim3 in the mid piece of the spermatozoa indicates decreased fertility. Further, the present invention refers to a dipstick usable for this method. Moreover, the present invention relates to further methods and uses in the context of the present invention.