By atomic force microscopy, the plastic deformation marks resulting from monotonic and cyclic plastic deformation were analysed to study the plasticity in each phase of Duplex Stainless Steels. In austenite, straight slip bands were observed after monotonic loading. These straight slip bands seem to serve as fatigue extrusion nucleation sites, which are the marks of the accommodation of the cyclic plasticity by the austenite. In ferrite, after monotonic loading, slip bands, could be classified into two different groups depending on whether they result from the bulk activities of ferrite or whether their formation is assisted by the plastic deformation of austenite. It was found that the crystallographic misorientation based on a Kurdjomov-Sachs relationship is the factor controlling one or the other type. After the first 5 loading cycles, the ferrite presents only monotonic plastic marks. This suggests no direct contribution of the ferrite to the accommodation of the cyclic plasticity.