Cognitive mapping has been a well known method for the elicitation, representation and analysis of implicit knowledge. Ontologies on the other hand have come into focus during the last decade to formalise, make explicit and machine-readable implicit knowledge. Nevertheless very few studies have examined the joint use of these two methods to improve knowledge sharing. The present research explores the development of a new method which uses cognitive mapping for the development of an ontology to support sustainable tourism policy making based on spontaneous argumentations and the natural language of policy makers. Results are encouraging and open a vast field of research in operationalising implicit knowledge, like the one that policy makers hold. Potential applications in the tourism field could involve e-tourism applications, destination management systems and travel planning tools for tourists.