The study of environmental impacts of tourist development has become a subject which attracts many researches and scientists, especially during the last decade. It is well documented that when the limits of tourist development are surpassed, many adverse and complicated effects are manifested. The intensity and magnitude of these problems become more prominent at places with special natural beauty, many aspects of which, are seriously threatened by many human activities. Not underestimating the contribution of tourism and the economic activities associated to it, towards the development of local communities, it must be stressed that, in many cases, tourist development characterised by the lack of long term goals and prospects, has been the main cause of much environmental and natural deterioration of many Greek island communities. It is certain that if no measures are taken and no methodology applied in order to ensure rational tourist development, the impacts can become quite serious and grievous in a very short period of time. Methodologies taking into account the capabilities of the areas concerned, as well as interventions respecting local conditions and environmental characteristics, such as the use of alternative energy sources, the implementation programmes based on ecotourism and the promotion of alternative tourism development in general, have been proposed by many researchers and scientists. Our research examines both negative and positive environmental impacts of tourist development in Rhodes, concentrating on issues such as natural resources and ecosystem management, the effects of human activities on fauna, flora and the coastal zone, leading to environmental indices for the island.[1] Data presented were collected from, personal interviews and all the local municipalities, state and municipal water supply, sewerage and electricity enterprises, the Union of hotel owners of Rhodes, the Prefecture of Dodecanisa including departments of environment, industry, agriculture, the port authority of Rhodes tour operators and local bibliographical sources.