The paper analyses the various impacts that nautical tourism has on the environment around the world, but with an emphasis on the Adriatic Sea and the Republic of Croatia. Although the impact on the economy is primarily positive, the impact of nautical tourism on the environment is mostly negative. Impacts arise as a result of the navigation of nautical vessels or as a consequence of the construction and operation of nautical tourism ports in which these vessels are located. During navigation, there are various negative impacts such as liquid, solid and gaseous waste, but also other impacts such as light, heat and physical disturbance of the environment. All of this primarily affects biotic environmental factors, but it also affects abiotic ones. Nautical tourism ports, and primarily marinas, also have a number of negative effects on the environment. Therefore, a number of measures are adopted at the domicile and international level in order to protect the environment as much as possible and to achieve the sustainable development of nautical tourism.