Abstract: The origin of the matter-antimatter asymmetry is one of the most important questions in cosmology. As the Standard Model cannot provide a satisfactory explanation of the baryon asymmetry, at present one of the most studied mechanisms to account for it is leptogenesis. The latter is particularly appealing because it takes place in the context of the see-saw mechanism, which at the same time naturally explains the smallness of neutrino masses. Establishing a connection between the parameters at
low energy (neutrino masses, mixing angles and CP-violating phases), and at high energy (relevant in leptogenesis) has gathered a great interest in the last few years. As the parameters in the see-saw models are more than the ones which are present in the low-energy effective theory and are in principle measurable in the present and future experiments, in general, there is no direct link between the two. However most specific models allow for such a connection. I will discuss in general the possibility to establish such a connection. Furthermore I will present two models in which the link is studied in detail: first a hierarchical see-saw model in which there is no direct connection between the magnitude of CP-violation effects in neutrino oscillations and leptogenesis, and second, the case of quasi-degenerate neutrino mass spectrum.