Juvenal’s satires present various figures of foreigners – especially Orientals, Jews and Africans. The author’s attention is focused in order to denounce the intrinsic danger of their customs in relation to the Roman ones. According to a typical post-colonial perspective, foreigners are an opportunity for the dominant culture to develop a dialogue with itself, denuncing bad behaviours which, according to the typical canons of satirical genre, become the subject of poetry.