The fight against discrimination has now become a major concern of the European Community. In this context, one issue has come to the forefront: that of the processing of data related to the forbidden grounds of discrimination, in particular racial or ethnic origin. Indeed, the experience of various countries demonstrates the critical role that data and statistics can play in the elaboration, implementation and assessment of policies aimed at combating racial and ethnic discrimination. Yet, many EU member states remain deeply reluctant to collect this type of data. The objection most commonly raised is that processing data on racial or ethnic origin would infringe upon the right to privacy. Two aspects of the right to privacy are at stake: first, it is widely believed that collecting these data would infringe personal data protection rules. Second, the idea of classifying people into racial or ethnic categories is itself contentious, as some fear it would conflict with the notion of individual self-determination. 
This paper aims to explore to what extent and under which conditions the data needed to combat racial and ethnic discrimination can be collected, while fully respecting the rights of individuals. Considering first the issue of personal data protection, the paper shows that although data revealing racial or ethnic origin are subject to a special protection regime under European personal data protection norms, their processing is not prohibited in an absolute way. Second, the paper examines the problem of constructing racial or ethnic categories and classifying individuals into them. It observes the emergence in international human rights law of a norm according to which classification of individuals into racial or ethnic categories should in principle be based on self-identification. It then considers the practices of four states in this relation: the United States, the United Kingdom and the Netherlands all have developed different classification systems for the purposes of their antidiscrimination policies. In France, by contrast, there is a priori a strong opposition towards classifying people on the basis of racial or ethnic origin. Yet, the idea of developing means to better measure racial or ethnic discrimination has emerged in the French public debate and is the subject of intense discussions. Examination of states’ practices enables to highlight the tensions and difficulties raised by the enterprise of classifying individuals into racial or ethnic categories in the antidiscrimination context. As far as classification criteria are concerned, it is argued that, despite their shortcomings, both self-identification and place of birth criteria are compatible with human rights requirements. The paper concludes that human rights standards, and in particular the right to privacy, do not preclude the collection of data on racial or ethnic origin for antidiscrimination purposes, but rather define fundamental safeguards that must be respected when gathering this type of information.