This paper sets a framework for intervention in the relationship between biodiversity and tourism against the background of the Convention on Biological Diversity. It is argued that intervention cannot and should not only be based on considerations of measurable impacts of tourism on biodiversity alone. This action should also be weighed against arguments of legitimacy, feasibility, and effectiveness of its various types. Currently, feasibility seems to be the main principle on which interventions are based. As most instruments are non-compulsory, they are effective only to a limited extent. For reasons of legitimacy, the position of small-scale entrepreneurs should receive more attention in international and national policy debates.