In this article the different meanings are explored from a gender-theoretical perspective that have been attributed to the phenomenon of intersex in western thought. While pre-modern thought was characterised by a ‘one-sex-model’ and relative tolerance towards perceived deviations from the masculine and the feminine, from the eighteenthcentury, the rise of biology, medicine and the two-sex-model led to a more strict classification of what are seen as normal and abnormal bodies. The second half of the twentieth century shows the rise of social constructionist thought and the malleability of gender role and identity. Despite the split between sex and gender, the binary sex/gender model remains unquestioned, until the contribution of critical gender studies in the nineties. However, the binary heteronormative model has long determined the modern medical treatment of intersex births. In the new millennium the medical field increasingly takes the criticisms from the growing intersex movement into account against unnecessary surgery, and in favour of more scientific research, evidence-based knowledge and sound follow-up of chirurgical and/or hormonal intervention in children with intersex/DSD, without their informed consent. The contribution of a gender-critical perspective is to keep exposing the limitations
of binary thought and to strive for more consciousness-raising about sex and gender variation, among stakeholders and the broader society.