Portuguese internationalisation policies essentially intend to promote an attitude favouring participation in internationalisation activities. However, as higher education institutions are autonomous, those policies aim at creating opportunities for development and management of these activities instead of imposing them. In this article we attempt to analyse Portuguese HEI responses to internationalisation. After reviewing briefly the recent changes in national and EU policies aiming at promotion of higher education internationalisation, we present the results of six organisational case studies, conducted with the goal of obtaining an answer to the question: how are Portuguese higher education institutions facing the internationalisation challenge? Based on the internationalisation profiles of the six institutions selected, we identify which factors foster and which factors impede the development of international activities at the organisational level in the Portuguese higher education system. Simultaneously we analyse the rationale explaining the different patterns of international activity between and within institutions.