So far, the Synthetic Control Method (SCM) has not been employed for evaluating the impact of tourism taxation. A lack of research on this topic is possibly due to the fact that, for example, in many European municipalities a tourism tax has been levied only very recently. Hence, the objective of the present paper is to investigate the effects of a taxation intervention on tourism flows by using the SCM. This work presents a case study based on a panel of municipalities in Sardinia (Italy), for the time span 2006-2011. Results highlight that tourism taxation has affected domestic and international tourism flows in a different manner. Applications to other contexts would guide policy makers on the actual effects of tourism taxation and related sustainable local policies.