Introduction: This paper presents an analysis of the Simple Knowledge Organization System (SKOS) compared with other alternatives for thesaurus representation in the Semantic Web. Method: Based on functional and structural changes of thesauri, provides an overview of the current context in which lexical paradigm is abandoned in favour of the conceptual paradigm. Likewise are described briefly various initiatives for the representation of thesauri using RDF vocabularies and hence for application to the Semantic Web, with particular attention to SKOS. Analysis and Results: This brief comparison will allow us to know some highlights of these proposals to raise those transcendental aspects in a model representing thesauri. SKOS includes the main proposal of this model, which organizes the concepts into diagrams and libraries. The notions of descriptors and non-descriptors terms are replaced by the association to the concepts of preferred and alternative labels and may be defined hierarchical or associative relationships between concepts. SKOS also provides for the establishment of correspondence relations between concepts belonging to different conceptual schemes. Conclusions: In accordance with the extent to which this series of requirements is fulfilled, we propose and defend the SKOS option as the best alternative for the development of multiple applications focusing on the use of thesauri in Web-based information services and systems, highlighting the advantages of this model over others proposed and in consideration of the user perspective in management, search and information query operations. (Contains 8 tables and 9 figures.)