The aim of this thesis is to, from a feminist point of view, analyse the Universal Decimal Classification UDC, which is an international and widely used classification system. A number of the larger classification systems and subject heading lists have during the last decades been placed in the limelight of various gender studies and the systems treatment of women has been criticized. With this examination of the UDC, I dont merely wish to identify shortcomings and advantages with the UDCs way to treat men and women. The UDC is also used as an example of how the gender problem can be identified and interpretated in classification systems generally. My analysis is performed with a theoretical foundation in feminist science theories about knowledge and norms, together with a linguistic perspective on valuing and emotionally tinged language. In the concluding discussion, I apply different feminist perspectives on the similarities and differences in the treatment of men and women found in the analysis. My conclusion is that the UDC has flaws in its treatment of women and in its possibilities to organize woman-related documents. The study reveals bias and a male norm in the system that contribute to the apprehension that women should be distinguished, thought of as differing from the norm and given a hierarchic suborder. The study also reveals an asymmetric treatment of the genders where the terminology, among other things, implies that the two genders should be treated differently. This is complex to interpret from a feminist point of view: Should documents related to women be given special treatment and thereby be given a front position in the system? Or, should all documents that include an aspect of gender be treated equally?