This study focuses on the dynamic behaviour of a small open economy specialized in tourism based on natural resources. The author analyses the steady-state properties in two scenarios, with and without public abatement expenditures, and a unique local saddle-point equilibrium is found for both cases. The analysis of the dynamics provides an alternative explanation for the observed positive growth performance of small open tourism-based economies and for the worldwide increases in tourist inflows, which are seen as transitional phenomena towards the path to the steady state. Moreover, in defining the conditions under which tourism development, improvements in environmental quality and economic growth can simultaneously occur, the model provides theoretical microfoundations for sustainable tourism. Finally, in both scenarios, the author analyses the issue of market failures, taking into account two different kinds of externality and finding the respective optimal tax rates that will induce private agents to replicate the social optimum.