The purpose of this dissertation is to describe and analyse the effects of tourism in developing countries and the attitudes and working methods of Swedish tour operators towards sustainable tourism. We have chosen to use a qualitative research according to a hermeneutical view. We have carried through in-depth interviews with eight tour operators. The theories have been divided into the effects of tourism and sustainable tourism goals which have social, economic and environmental starting points. The empiricism describes the work and activities of the tour operators and compiles the interview material divided into attitudes on tourism effects and responsibilities. The section is completed by the realisation of the above. In the analysis and conclusion we discuss that the tour operators find the environmental effects to be the greatest issue and that they believe that they do take responsibility. Although we think that they do not take enough responsibility to reachsustainable tourism.