Environmental resources constitute the ‘raw materials’ for tourism. This sector represents the driving force behind the economy of small islands. The sustainable use and a rational policy of conservation of these resources are prerequisites to enable their full exploitation. However, island systems have low stability, as they are highly sensitive to exogenous stress phenomena caused by economic factors, which exceeding the sustainable threshold may come together to damage the environment. This work systematically examines the effects and the feedbacks that the economy of tourism may generate in small areas like the minor islands of Sicily (Italy). The development of a dynamic model is proposed to supply a key to interpret the phenomena affecting the island of Salina (Aeolian islands-Messina) offering elements for the assessment of future local government policies.