The title and topic of this paper is Potentials of eco-tourism development in the Republic of Croatia. The Republic of Croatia is known around the world as a very famous tourist destination and is a special competitive and attractive location for new investments and for the arrival of a large number of guests throughout the year, but especially in the summer months. First of all, the Republic of Croatia has in mind to preserve its own natural beauties and landscapes in order to offer them to its visitors. In this final paper, the general concept of eco-tourism will be discussed and the criteria for its development will be stated. Then, the paper will provide relevant information regarding eco-tourism in Europe. Eco-tourism in the Republic of Croatia is a central part of the work. In addition to the above, the impact of the COVID 19 pandemic is also described in the paper. Ultimately, the paper will state what are the guidelines for sustainable development of eco-tourism, what are the challenges of eco-tourism and the problems. The aim of this paper is to show the potential development of ecotourism in the Republic of Croatia, which is located in a favorable geographical area and which has recently made certain efforts in the development of eco-tourism. In addition to the above, through the prism of sustainable development, the tendencies of Croatian tourism in terms of eco-tourism will be presented. Emphasis will also be placed on the COVID 19 pandemic. The aim will be to show the far-reaching impact of the pandemic on the overall tourist picture of the Republic of Croatia and with an emphasis on eco-tourism.