The study examines the attitudes of local residents toward the impacts of sustainable tourism development in two national parks in Montenegro—Skadar Lake National Park (NP) and Durmitor National Park (NP). The aim is to identify the key factors shaping these attitudes and to determine the differences in perceptions between residents of these two areas. The research is based on the assumption that socio-demographic characteristics, such as gender, age, and level of education, significantly influence attitudes toward sustainable tourism development. Data were collected through a questionnaire covering a wide range of attitudes toward tourism. Analyses were conducted using multiple regression analysis, one-way analysis of variance (ANOVA), and Pearson’s correlation, with careful verification of all key statistical assumptions to ensure the validity of the results. The findings reveal significant differences in perceptions between residents of NP Skadar Lake and NP Durmitor. Respondents from NP Durmitor generally rated both the positive and negative aspects of tourism higher compared to those from NP Skadar Lake. On the other hand, residents of NP Skadar Lake exhibited greater enthusiasm for tourism promotion and engagement in tourism development processes. It was concluded that socio-demographic characteristics, particularly education and age, are key factors influencing attitudes toward tourism. These findings provide a basis for formulating recommendations to improve tourism development, which should take into account the specific needs and perceptions of local communities in both national parks.