This technique is the first to enable the reconstruction of the vectorial magnetic geometry of stars similar to the Sun. It is now offering the opportunity to undertake systematic studies of stellar magnetism and is also yielding information on the geometry of large arches that magnetic fields are able to develop above stellar surfaces. To collect the observations related to Zeeman-Doppler Imaging, astronomers use stellar spectropolarimeters like ESPaDOnS at CFHT on Mauna Kea (Hawaii), HARPSpol at the ESO's 3.6m telescope (La Silla Observatory, Chile), as well as NARVAL at Bernard Lyot Telescope (Pic du Midi de Bigorre, France).