Brazil combines acute and complex socio-environmental problems and a techno-scientific potential able to cope with it by producing knowledge for social development. Its past shows that when there was the political will to produce the knowledge needed to achieve the goals of a national project, this potential could respond satisfactorily. As suggested by the title, this paper discusses why science and technology (S&T) capacity building is relevant for social development goals. It presents 'the stage we are at' concerning the demand side, the supply side, as well as the political side of Brazil's current environment of S&T for social development. These elements help us trace some policy directions on how to achieve S&T for social inclusion, presented as an agenda for future actions.395548556