This paper highlights the interdependence of tourism and the environment. While on the one hand, tourism brings great significance to the national economy, on the other hand, tourism is dependent on the environment and its resources, which are the main source of tourism. The development of ecotourism has so far been based mainly on national parks and protected areas, but as awareness of sustainable development is increasing year by year, eco-tourism is increasingly being developed in agricultural economies. Ecotourism in the Republic of Croatia is still not developed and is not at the level it could be with respect to all the natural beauties, riches and resources that Croatia has. Therefore, it is potentially necessary to valorize and protect it in accordance with sustainable development, which today increasingly wants to meet the wishes and needs of tourists and at the same time preserve nature and its wealth. One of the main reasons for the lack of ecotourism in Croatia is certainly maritime tourism, according to which everyone is focused on, because of the great economic benefit that is realized in just a few months of work. There is also serious lack of economic incentives for eco-tourism development, which, of course, has a major impact on the development of eco-tourism. For ecotourism, we can say that it is one of the most promising forms of tourism because trying to meet the needs of tourists ecotourism orients itself towards the preservation of nature and the environment, but also the existence of the local population.