Résumé : At a time when the liberalisation of air transport is increasingly being promoted as a means to induce the growth of the tourism business, it is striking that there is little evidence to suggest that such liberalisation has indeed led to a growth in tourism. Furthermore, the evidence is usually restricted to the impacts of sole low-cost airlines on tourist destinations newly served by such airlines. In contrast to various ideological or naïve statements, this paper shows that assessing the relationship between liberalised air markets and trends in tourism is challenging. On the transport side, aviation liberalisation is rarely considered as a dimension that can be measured accurately; similar protected markets are not considered for comparison; and trends in charter flights are neglected. On the tourist side, broad definitions of so-called tourists are usually considered and include immigrants visiting their home country; nights spent are neglected, despite a possible trend in declining length of stay; and substitution between places is usually disregarded, as are the long-term effects.