In Greece, the institution of protected areas, which also include national parks, has been undergoing a transitional period at present, under the impact of the needs of modern society, national policies and the community directives regarding regional development and environmental protection. The National Park of Dadia-Lefkimmi-Soufli in northeast Greece carries a major ecological value due to the existence of a large number of birds of prey. The main aim of the presented study was to analyse visitor satisfaction and perform segmentation analysis in order to identify the different groups of visitors and estimate the homogeneity of preferences in distinguished visitor segments. In order to analyse the collected data, several statistical and data analysis methods (i.e. chi-square test, confirmatory factor analysis and cluster analysis) were applied. The results show that the majority of the visitors are generally satisfied with the quality of the provided services, while additional findings may help the park's managers to further improve the offered services, thus contributing not only to an increase in the overall satisfaction of visitors, but also to the development of the region as a whole.