We are witnessing the period of increased migration mobility in history and, although the reasons for this continuous flow are diverse (war conflicts, geo-economic inequalities, etc.), one of its most notable consequences is the increasing concentration of minority groups in some societies, to the point that they become a genuine multicultural crucible. In this context, the attitudes that members of such societies develop towards such groups are key to facilitating their integration and peaceful, harmonious and win-win coexistence. But prejudice, understood as a negative assessment towards another social group, is inherent to any society and particularly relevant when analysing inter-group conflicts. Moreover, once formed, prejudices tend to self-perpetuate over time, even become truly resilient to change. The aim of this work is therefore to address this social problem on the basis of a broad theoretical review of prejudice and the various proposals to reduce it.