Tourism is one of the most dynamic and the fastest growing economic activities. Nowadays it is characterized by more and more demanding tourists and stronger competition among tourist destinations all over the world. Destinations look for ways of keeping the existing visitors and attracting the new ones. Dynamic surroundings and obligations towards present and future generations impose the need for quality strategical planning and acting, in concordance with defined development plans based on sustainable development. Tourism creates significant economical, ecological, cultural and social influence upon a tourist destination. Besides positive influences, tourism also has negative ones which are manifested primarily through degradation of environment and cultural heritage. In the same time development of tourism depends on the quality of the environment and the preservation of cultural heritage in the destination. That is why planning and managing the development of tourism according to the principles of sustainable development is of utmost importance. At the level of tourist destination in the Republic of Croatia there is an inadequate development planning and „ad hoc“ measures, and also an inadequate cooperation among main participants in planning and managing tourist development on a local level. Expectations are mainly focused towards tourist offices and boards, so their engagement and activities are the main factor in destinations success, and in the same time local governments are only passively involved in planning and managing tourist development, for example by helping financially or technically in some projects or events. One of the problems is too small municipalities and cities that have limited capacities for adequate planning and managing tourism. Engagement of a city or a municipality often depends on personal preferences of one or more leading people (eg. the mayor). When we talk about the sustainable development, it can be noticed that local government often uses that notion in various documents and public speaking, without concrete measures and steps in planning and promoting sustainable development. It is also questionable if the understanding of meaning of sustainable development and its components is clear, when this notion is used in local government documents or their representatives' statements. Besides, if sustainable development is even promoted, it is not certain that an equal attention is given to its basic categories (ecological, economical and socio-cultural), or if the indicators for measuring progress to sustainability are determined. To realize needed changes, certain steps on the local level are necessary. Participants in planning and managing of tourist development have to take their role in planning and promoting sustainable development seriously. Local government should have the main role in promoting and coordinating this Mičetić Fabić M.: „Uloga lokalne samouprave u planiranju i promicanju održivoga razvoja turističke destinacije“ IV development, since it is responsible for protecting local interests and taking care of economical and social development in its area. Local governments knows the local population's needs best, and it should be impartial and entirely focused on those needs. Chapter 28 of Agenda 21 talks about the importance of local government in planning and promoting sustainable development. Participation of local government is crucial for realizing aims of Agenda 21. Beside local government, main participants in planning and managing tourism on local level are tourist boards, private sector and local population. Making and adopting strategic plans, implementation of targeted measures, projects and programmes, defining and tracking progress indicators etc., are only some of important activities that all of the participants have to carry out if the desired vision of a sustainable development is to be achieved. The aim of this thesis is to determine whether the units of local government carry out planning and promoting sustainable development in appropriate way, in concordance with their own and other strategic documents related to the development of a tourist destination. Furthermore, whether they have plans that contains initiatives/activities for planning and promoting sustainable development, whether they have and apply indicators to measure progress towards sustainability, if they have carried out an adequate organizational adaptation to planning and promoting sustainable development, and finally whether they take care of ecological, economical and socio-cultural sustainability in equal measure. It is also being determined what obstacles and problems local governments deals with when implementing activities for sustainable development. For the purpose of making relevant conclusions, two primary researches were done as part of PhD thesis; one on the sample of Croatian experts and scientists that deal with sustainable development and/or tourism, the other on the sample of Croatian cities in seven Croatian coastal counties. After that, related statistical analysis were carried out to determine correlation of applying promotion of sustainable development with sustainability indicators in those tourist destinations, and to determine existence of statistically significant differences in applying promotion of sustainable development among counties, then among cities situated on the coast and in the coastal hinterland, and bigger and smaller tourist destinations. Based on the results from researches and analysis, appropriate conclusions were made. Units of local government in Croatian coastal counties implement various initiatives/activities to promote sustainable development and give them high or higher level of preference than to some other activities. But considering that observed initiatives/activities in this doctoral thesis are very important for sustainable development of the destination, worrisome results are that many of analysed initiatives/activities are performed with low/the lowest level of preference, and some of the observed cities do not carry out some of initiatives/activities. The biggest obstacles and problems in applying activities for sustainable development are lack of financial resources and variability of legal regulation, lack of human resources in city administration, inadequate education of available human resources, inadequate cooperation among main participants in a destination, as well as non cooperative business sector. Cities have made formal strategies, strategical and action plans containing aims of sustainability. Mostly those are development strategies, economic development strategies, tourism development strategies and plans for sustainable development in the field of energy. Sustainable development as a concept appears in those documents in defining visions, strategic goals and priority measures. Research about the presence of principle of sustainable development in strategic plan documents of monitored cities shows that in most cities all three components of sustainability (economic, ecologic, socio-cultural) are represented completely or largely, indicating the equal representation of all three components in strategic development plans. Although the possibility of measuring progress towards sustainability is very important for a successful management, local government often do not have defined indicators to measure realized progress in the area of sustainable development in their documents, consequently they are not used; or they have them defined, but still don’t use them. Research done as part of PhD thesis has shown that local governments carry out various activities to promote sustainable development, but they are not always in concordance with activities envisaged in development strategies, strategical and action plans. Although the cities that are also tourist destination are expected to carry our organisational adaptation to jobs related to planning and development of tourism, research results show that 55,3% or 21 monitored cities have an employee or an organisational unit for these jobs, but only four cities have the word tourism in the name of a working place or organisational unit. When it comes to sustainable development, 42,1% of surveyed cities applied some form of organisational adaptation to jobs related to planning and promoting sustainable development and 26,3% have specifically defined an employee or an organisational unit formally in charge of planning and promoting sustainable development. However, that data becomes questionable when titles of those jobs or organisational units are observed, since mostly those are usual work places or organisational units and not special ones that deal with sustainable development. There are only few cities where the focus to sustainable development is visible in the name of a working place or an organisational unit (eg. Administrative department for sustainable development). In this thesis it has been partly confirmed that between application of sustainable development in tourist destinations and sustainability indicators of tourist development there is a positive correlation, but only in some of monitored variables. It has also been partly confirmed that among counties, among cities on the coast and in the coastal hinterland, and among smaller and bigger tourist centers there are statistically significant differences in applying promotion of sustainable development in tourist destinations. In accordance with the set aims, measures for stronger role of local government have been suggested, both in planning and promoting development according to the principles of sustainable development and the proposal of a model for planning and promoting sustainable development of tourist destination is suggested, with a special emphasis on the role of a local government.