The promotion of rural tourism is one of the measures that has aroused most expectations in the application of the endogenous rural development programmes promoted by the European Commission at the beginning of the 1990s. Using the case study methodology, this research aims to compare the implementation of the aforementioned measure in two regions which, according to their characteristics, could be considered as antagonistic examples: one, La Vera, has all the conditions to successfully develop its tourism sector; the other, Tajo-Salor, with an adverse climate, lacking in outstanding tourism resources and far from the main centres of demand, could be considered the opposite. The results of the research show the risks inherent in an excessive specialisation in tourism within development strategies. Paradoxically, in La Vera, the concentration of investment in the tourism sector has resulted in a higher number of failed and transferred projects, as well as the dissatisfaction of most of its tourism promoters with the viability of their businesses. In contrast, in Tajo-Salor, the results are more positive, despite the fact that this region has given less relative importance to the tourism sector.