The generation of solid waste is one of the major environmental issues in mountain areas with high concentrations of tourism. To improve the waste situation in sensitive mountain areas, visiting tourists need to be aware of the impacts and consequences of their waste practices. Educational programmes play a crucial role in improving the waste situation, but are ineffective if they do not consider different target groups. The main purpose of this paper is to explore different types of tourists based on their reported waste practices, environmental concern and personal responsibility. A survey based on a convenience sample of trekking tourists was conducted in Sagarmatha National Park and Buffer Zone in Nepal during the spring season of 2013 (n=335). The obtained results of the cluster analysis point to segment specific differences in visitors’ environmental attitudes and behaviours. Managerial implications of the findings may help to develop effective educational strategies and thus contribute to the improvement of the rapidly growing waste issues in mountain regions.  Keywords : Mountain Regions; Consumer Behaviour; Tourism Segmentation; Environmental Behaviour; Sustainable Development; Waste Management