This study investigates the attitudes of local residents regarding 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 that shape these attitudes and to discern the differences in perceptions between the 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 various 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 tourism’s positive and negative aspects higher than those from NP Skadar Lake. On the other hand, NP Skadar Lake residents exhibited more enthusiasm for tourism promotion and engagement in tourism development processes. It was concluded that socio-demographic characteristics, particularly education and age, influence attitudes toward tourism. These findings provide a basis for formulating recommendations to improve tourism development, considering local communities’ specific needs and perceptions in both national parks.