This paper presents a critical discussion of the internationally prevailing understanding of the concept 'sustainable tourism'. It is argued that the current focus on stationary activities and local, intensive environmental issues is too limited both in relation to the concept of tourism and the concept of sustainable development. There is no tourism without travel. And, as shown in a Norwegian research study, tourist travel is a major source of serious environmental problems. The paper emphasises that sustainable tourism should be linked to a concept of sustainable mobility. However, this mobility would imply not only a change in the means of transport but also a reduced level of mobility in the rich part of the world. As this would entail new forms of tourism, other than those solely based on auto- and aeromobility, it represents a major challenge for the future development of tourism.