Since the late 1990s, several studies addressed the future of the European population and the role that international migration can play in offsetting population decline and slowing down ageing. These studies have been produced for several European contexts, including the Southern European one, where the pace of ageing has been faster than the average. In a context of population ageing, the impact of the migratory flows in the Portuguese demographic structure is also a non-negligible element to consider. Despite the difficulties associated with the forecast of the migration component, due to the volatility of the international migratory flows, as well as to the shortcomings of the available databases, the main goal of this study is to evaluate the impact of different migratory scenarios in the expected population structure in Portugal (for the period 2009-2060, based on the cohort component method, with only one scenario for mortality and fertility).

Key-words: migration, ageing, population projections.