The paper looks first at the geographical conditions, specifically the economic, socio-cultural, demographic, and environmental, including local conditions as the vital factor underlying the course of transformation in mountainous rural areas. Next, the paper considers the results of the case study from the Pol'ana Biosphere Reserve (BR) in Central Slovakia, which is an excellent model territory for studying man and nature relationships. Basic socio-demographic data on population of the BR are analysed and their relations to quality of life and sustainability are discussed. Selected aspects of sustainability and the life quality of population in the BR are studied in the analysis of recent situation using subjective estimates of local decision- and opinion-makers. The research (interview technique) is focused on the evaluation of perception of environmental and nature conservation problems, community's milieu, community development, and on the evaluation of the opinion about the community, regional sustainable development programmes and improvement of life quality. Finally, several conclusions important for future role of human factors in sustainable development of mountainous rural areas are presented as well as the list of the most important challenges for mountainous rural areas from the perspective of sustainable development.