Machines and structures are composed for elements which are subject to fatigue, which is one of the factors determining the lifetime of the links. The fatigue life is divided into three stages: initiation or crack nucleation, propagation and failure. It is very important to study the initiation stage of fatigue cracks, as it can become 90% of the total life of the component. Currently, the finite element modeling (FEM) depends largely on the density of the mesh around the crack tip, the overlock (if required), the type of analysis, either bidimensional or three-dimensional; which implies a high cost of computer simulation. In this paper the different finite element models and experimental tests of fatigue crack initiation, taking into account the different methodologies, geometries of parts, reliability of data, among others will be studied.