Background. Valuable natural areas are significant tourist destinations. However, a large number of tourists is a threat to sensitive mountain ecosystems. Thus the Spain pay particular attention to sustainable development, especially where nature can be mostly endangered. The article is an attempt to assess the state of selected elements of tourism in mountain national parks of Spain and the perspectives of their development. Material and methods. The main method is an analysis of statistical data referring to the accommodation infrastructure of rural tourism, especially of protected mountain areas, as well as data concerning tourist traffic. Results. The most important forms of tourism practiced in natural areas are presented; the importance of rural and nature tourism is emphasized in the context of sustainable development. The main issue that influences the development is accommodation infrastructure. Taking into account the perspectives of tourism development in the mountainous national parks, the need to create an offer more open to foreign tourists was underscored. Among the threats, the problem of unifying accommodation units operating in the rural environment was pointed. The solution demands changing legal situation and the competences of the Spanish autonomic regions, which seems to be a difficult task. Conclusions. Tourism in the mountain national parks of Spain functions properly based on the tourist attractions, and the development perspectives are good provided that the question of systematizing accommodation unit types is solved, and efforts to attract foreign tourists are undertaken.