This paper contributes to the research into the sustainable development of tourism. It analyses large-scale protected areas (one national park, four landscape parks, two protected landscape areas) located in the Roztocze region, at the SE border of Poland, which are most exposed to tourist movement overload due to their attractiveness. The study presents a proposal for a research procedure based on the method of multidimensional comparative analysis, which facilitates interpretation of the state of tourism function by calculation of the values of indicators of tourism potential and function. The result of the study is a model. It shows that with the exception of the National Park, the current state of tourism can be described as sustainable in most of the analysed areas. In addition to their scientific value, the results obtained may have a practical dimension, as they indicate specific factors causing the loss of balance in the environment, which should be monitored or addressed by stakeholders (government, local authorities, entrepreneurs, local communities), leading to the maintenance of sustainable tourism development in a specific area. The procedure proposed in the study can be applied to any other naturally and culturally valuable area.