This paper explores expert witnessing in anthropology and the raison d'être of cultural expertise as an integrated socio-legal concept that accounts for the contribution of social sciences to the resolution of disputes and the protection of human rights. The first section of this paper provides a short historical outline of the occurrence and reception of anthropological expertise as expert witnessing. The second section surveys the theoretical reflections on anthropologists' engagement with law. The third section explores the potential for anthropological expertise as a broader socio-legal notion in the common law and civil law legal systems. The paper concludes with the opportunity and raison d'être of cultural expertise grounded on a sceptical approach to culture. It suggests that expert witnessing has been viewed mainly from a technical perspective of applied social sciences, which was necessary to set the legal framework of cultural experts' engagement with law, but had the consequence of entrenching the impossibility of a comprehensive study of anthropological expert witnessing. While this paper implies a sceptical approach to culture, it also argues the advantages of an interdisciplinary approach that leads to an integrated definition of cultural expertise.