Knowledge management is a big challenge especially in large organisations. Knowledge resides in many different forms: as explicit knowledge in documents and processes and as tacit knowledge in people and procedures and in many different forms between these two extremes. The vision of the Semantic Web is to offer more intelligent services by facilitating machineunderstanding of web content. Ontologies are an important building block in Semantic Web. An ontology describes the concepts, their relationships and properties within their domain, and it can be utilised both to offer automatic infering and interoperability between applications. This is an appropriate vision for knowledge management, too. This paper describeshow Semantic Web ontologies can be utilised in a research organisation to create a common language to describe its knowledge. The same ontology can be utilised to manage projects, people, documents and products. With a common ontology, information that is spread out in many different applications and documents can be viewable in a way that is easyto understand and navigate. The ontology makes it possible to search both knowledge content and experts who are linked to different topics, thereby bridging the gap between the tacit and explicit knowledge.