In this paper data on fatigue lifetime of nanocrystalline (nc) Ni samples is presented. The nc-Ni samples show high lifetimes and can resist large stress amplitudes. Furthermore a new method to determine the fatigue limit based on a Fourier analysis  is presented. First results of a load increase test suggest strong parallels to thermal and resistive measurements which can be used to determine the fatigue limit. Microstructural investigations on as received and failed samples show a strong increase in grain size induced by the cyclic loading. The processes behind this are not understood so far and will be investigated in the future.