The massive stars are the progenitors of the supernovae and neutron stars. All along their lifetime, they are powerful cosmic engines that have a strong influence on the structure and composition of their host galaxies, and their surroundings. Although the existence of magnetic fields in massive stars is no longer in question, our knowledge of the basic statistical properties of these fields is seriously incomplete. In particular our knowledge of the origin of the magnetic fields, the impact of these fields on massive star evolution and mass loss, and of the physics of magnetospheres is very poor. In order to shed light on these problems, a large International collaboration, MiMeS (Magnetism in Massive Stars), have started a theoretical and observational program, using the new generation of spectropolarimeters ESPaDONs (at CFHT), and Narval (at TBL). In this talk I will present the latest results of the MiMeS project, expose the basic properties of magnetism in massive stars that we could draw until now, and how they compare to the intermediate and low-mass stars.
