Cosmology and CP Violation

We describe the role of CP violation in the generation of the baryon asymmetry of the Universe, in the framework of baryogenesis through leptogenesis, with emphasis on the possible relationship between CP violation at low energies and that required by leptogenesis. It is emphasized that a direct link between these two manifestations of CP violation only exists in the framework of specific flavour structures for the fundamental leptonic mass matrices.