There are numerous studies which point to the possibilities for rural revitalization and improvement of the living standards of the rural population through development of tourism. Cluster concept and regional cluster initiatives in tourism are generally presented as tool for fulfilment of ideas about the successful regional and rural development. This study presents the genesis, functioning and impact of two tourism cluster initiatives from mountainous rural areas of Slovakia (Orava region and Turiec region) on selected regional indicators (net migration of population, number of tourists, overnight stays and unemployed persons) with the aim to confirm or put into the question the validity of positively perceived direct relation between the simple existence of tourism cluster and racional (successful and/or sustainable) spatial development. The results (comparison of applied regional indicators before and after establishment of tourism clusters) show that establisment and existence of tourism clusters in Orava and Turiec regions are not automatically accompanied by the dramatic changes of regional and rural economic prosperity and/or sustainability in the first years of their activities.