In the past couple of decades, the creation and management of the tourist destination brand has been a dominant field of research in tourism. Because the development of tourism has been getting increasingly larger and more complex, with the number of tourists consequentially increasing, tourist destinations are differentiating themselves from each other through their brands. However, the effects of tourism also have a negative aspect, one which calls into question the sustainability of the destination, i.e., the use of resources for both the future generations and for the better quality of life of the local residents. The brand creation concept is a significantly untapped potential for tourist destinations, especially the one that is based on the sustainable development of tourism. The subject of this doctoral dissertation deals with establishing a model for creating a tourist destination brand based on the principles of the sustainable development of tourism with the goal of increasing the competitiveness of destinations. It is important for tourist destinations to implement the principles of the sustainable development of tourism so that tourism can transform within a destination in a way that enables better development and, consequently, long-term prosperity. The analysis of the relevant literature in the theoretical section of the dissertation, which studies the aspect of sustainability and the concept of sustainability within the context of the development of tourism, places a special emphasis on explaining the concept through goals, through sustainable and responsible development and through the significance of the implementation of the sustainable development of tourism. The overview of the platforms for the sustainable development of tourism provides a detailed insight into the individual elements of the concept of the sustainable development of tourism. The guidelines for creating brands are created by way of theoretical insights into the tourist destination brands, while the destination tourist product is defined as the basis for creating the brand. As the guideline for destination development, competitiveness is elaborated from a theoretical aspect by way of the connection between the sustainable development of tourism and the tourist destination brand, and the concept of competitiveness is explained. Secondary research, during which literature was consulted, was followed by defining the indicators for measuring the stated concepts. The conceptual model of the doctoral dissertation was also specified. The tourist destination brand is a complex process that requires time and a holistic approach. The sustainable development of tourism is a tool used for creating the tourist destination brand and for competing with other tourist destinations. By applying the concept of sustainability, a tourist destination may position itself on the market better, a more favourable brand image may by constructed for the destination, and a contribution to the development of the economy and tourism can be made. The contribution provided by the sustainable development of tourism is key for achieving the goals of a destination. A tourist destination that creates its brand on the premise of sustainability is the backbone for competitiveness and for a better quality of life of the local residents. After establishing the conceptual model, a survey was used in the empirical part of the research. The participants were locals employed in tourism in seven Croatian destinations (Dubrovnik, Mali Lošinj, Split, Poreč, Knin, Osijek and Zadar) that were selected on the basis of several criteria: investments in the sustainable development of tourism, number of inhabitants, number of visitors, awards awarded to tourist destinations by specific institutions. A total of 748 fully completed surveys was collected. This was the research sample used for analysing the established conceptual model. The statistical methods of univariate, bivariate and multivariate analysis were used for analysing the doctoral dissertation, for testing the hypotheses, and for deriving conclusions. The univariate statistical analysis methods, such as descriptive analysis with average grades and standard deviations, as well as the analysis of answer frequency, were used for analysing the research sample. The bivariate statistical analysis methods, such as correlations and variance analysis, were used to determine the connections and differences between individual destinations in the research sample. The following multivariate statistical analysis methods were also used: exploratory factor analysis for determining the dimensions of the factors in the research and for certifying the measurement instrument, and multiple regression analysis for establishing the connection between independent and dependent variables. The validity and reliability of the measurement instrument, i.e., of the individual factors in the research, were checked using Cronbach's alpha, average isolated variance and construct reliability. The primary research done on the basis of statistical analysis proved and explained the variables of the conceptual model of this doctoral dissertation. The empirical research established a statistically significant connection between the sustainable development of tourism and the tourist destination brand. The multiple regression analysis established the share of investments in sustainable development in selected cities, as well as identified the consumer-based equity of the tourist destination brand on the basis of the perception of the local residents. The tourist destination brand is formed on the basis of applying the principles of sustainable in tourist destinations, i.e., the investments in environmental protection. The tourist destination brand requires that clear recognizable platforms are defined. For the purposes of competitiveness, the cornerstones for tourist destinations are image, identity and other similar elements. In this doctoral dissertation however, competitiveness is, for the created tourist destination brand, based on the principles of the sustainable development of tourism. Therefore, a tourist destination competes on the tourist destination market by way of its brand. The purpose lies in the creation of the tourist destination brand, as the concept of this doctoral dissertation represents the model for the creation of the destination brand, while the goal of the dissertation is to provide an answer to how to increase the consumer-based equity of the destination brand, which is achieved by applying the concept of the sustainable development of tourism. The concept of creating the tourist destination brand gives guidelines for managing tourist activities and for developing the destination in order to achieve the requirements for a destination to be competitive. For a further analysis of tourist destinations according to their sustainability, brand and competitiveness, three groups of destinations were formed according to investments in environmental protection per capita. The highest rate of investments in environmental protections by local government and self-government was recorded in Mali Lošinj, while the lowest was recorded in Split. Poreč and Mali Lošinj were thus placed into the high investments per capita group, Knin, Zadar and Dubrovnik were placed into the medium investments group, while Split and Osijek were placed into the low investments group. Survey participants in destinations with high-level investments in environmental protection gave higher average grades, while lower average grades were given to destinations with low investments in environmental protection. With regard to the sustainable development of tourism, it is statistically important for destinations with high investments in environmental protection to become aware of the importance of perceived social costs, perceived economic benefits and community participation in comparison to destinations with medium and low investments, while destinations with high investments in environmental protection differ from those with low investments in the way how environment sustainability is perceived. Destinations with high investments in environmental protection differ from those with medium and low investments with regard to those elements of the tourist destination brand that relate to brand consciousness, brand quality (employees) and brand image. On the other hand, destinations with high investments in environmental protection differ from those with low investments with regard to the perception of brand loyalty. When it comes to destination competitiveness, the statistically most significant differences between the three levels of observed destinations are those that relate to the destination’s historic characteristics. In order for the sustainable development of tourism to affect the creation of the tourist destination brand, investing into the perceived economic benefits and decreasing the perceived social costs have the greatest importance. The sustainable development of tourism has the greatest effect on those elements of the tourist destination brand that represent brand image and brand consciousness. If a destination wants to use the tourist destination brand to achieve a competitive advantage, the greatest importance when creating that competitive advantage is given to the destination’s location characteristics. During this, the greatest attention should be given to brand loyalty, that it, to the development of brand loyalty. With the goal of developing the competitiveness of a tourist destination, significant investments in the tourist destination brand are required in order for the local populace to act in a way that displays their loyalty to the destination in which they live and that shows that they regard the destination as their first choice for living. The results of the empirical research shall be of use to the tourism sector. Specifically, to destination managers who make decisions relating to the tourism development segment, to local self-government when implementing the principles of the sustainable development of tourism, to business entities, and, ultimately, to the local residents who need to be aware that they themselves are a resource that creates the tourist destination brand and that consequently contributes to achieving the tourist destination's competitiveness. The scientific contribution of the doctoral dissertation is presented in the proven correlation between the sustainable development of tourism and the tourist destination brand, with emphasis placed on the significance and importance of the sustainable development of tourism for the purposes of achieving competitiveness. The sustainable development of tourism has the role of decreasing the negative effects of tourism and of preserving resources that may be of use to future generations. Furthermore, it serves to increase the consumer-based equity of the tourist destination brand, which is reflected in the destinations’ competitiveness. The local residents has the most important role in the creation of the tourist destination brand. They affect the processes and the development of the tourist destination. They present a way for destinations to differentiate themselves and to be competitive in the tourism segment.