Sustainable development is a concept that recognizes meeting the needs of present generations without compromising the needs of future generations as a fundamental guideline for developing societies and economies, which needs to be included in the process of holistic planning at all management levels. This paper aims to identify, based on theoretical knowledge of economic, environmental and social developmental factors, the current state and future perspective of Istria county in terms of its sustainability. The final aim of this paper is to assess the possibilities for sustainable management of future county progress, taking into consideration trends within each development dimension. The methodology used includes methods of strategic and holistic planning along with other methods of scientific research. The conducted analysis showed solid foundations for sustainable development of Istria county, with the provision that the existing key obstacles across all dimensions will be resolved. To achieve sustainable progress, it is necessary to address the problems of socio-economic divergence between the coast and inland, mitigate the effects of ongoing negative demographic trends, and develop technological-industrial sectors to reduce population's dependence on seasonal tourism movements.