The overall aim of this qualitative study is to investigate the area of new sustainable tourism in theory and practice. The theoretical part, which consisted of a literature study, was made to help find the essence of new sustainable tourism. To bring out tourisms impact on society and environment in practice, a case study was made during an excursion with Södertörn University College to Babati in Tanzania. Semi structured interviews were held with people in Babati. The excursion is being evaluated according to WTO’s sustainable tourism development guidelines and management practices, and finally, these guidelines are analysed. The result of the literature study showed that there is no absolute true core in new sustainable tourism. It is a highly subjective judgment if a tourism venture is sustainable or not, depending on personal values, ideology and personal interests. There is features commonly associated and used in new sustainable tourism, like the sustainability of the three pillars of sustainable development, and the focus on the local, educational and conservational effects, but the essence is subjective. The evaluation of the excursion showed that it is by two third a sustainable tourism venture. It is the economic part that fails, since the guidelines put much focus on stable employments and frequency; ingredients that the excursion lacks. The analysis of the WTO guidelines resulted in confusion. They could be both very useful, but also very poor, according to how they were interpreted and used. The results highly depend on the user. Positive is that the guidelines address all pillars of sustainable development equal, and that the interaction between host and guest gets highlighted. Shortages are that the guidelines lack a gender perspective, a historical and political sensibility, a place specific flexibility and a perspective of inter- and intra-generational equity.