This paper offers a systematic reconstruction of racialisation as one of the most promising theoretical approaches available today in order to explore racism as a social and legal construction. Contemporary European societies are experiencing a sort of paradox: they see themselves as post-racial, as far as the biological-historical notion of 'race' has become a taboo after Auschwitz and has been scientifically defeated; at the same time, they face the proliferation of new forms of racism. This is why this paper argues in favour of a paradigm change, from 'race' to racialisation. This change of perspective allows, in the first place, to understand how essentialised and naturalised notions of culture, identity, religion, migratory status, etc. have replaced 'race' in current discourses and practices aimed at discriminating people because of their (alleged) belonging to some racialised group. The reconstruction covers four key acts of racialisation - epistemic, axiological, ideological and repressive - while analysing their 'logic' and exploring their interconnections. In conclusion, fundamental socio-economic and political functions of racialisation are assessed, in order to clarify who profits from the proliferation of new racism and whose interests have to be challenged if structural racial injustice has to be reduced.