Protected areas are regarded as the main strategy to halt biodiversity loss; however, protected area effectiveness evaluations remain scarce and mostly rely on limited scientific evidence. Protected area managers from two case studies in the Mediterranean basin biodiversity hotspot (networks of Spanish terrestrial protected areas and individual Mediterranean marine protected areas) were surveyed to assess the use of two protected area evaluation systems: the ‘System for the Integrated Assessment of Protected Areas’ (SIAPA) and the ‘System for Quick Evaluation of Management in Mediterranean MPAs’ using the ‘Knowledge Systems for Sustainable Development’ framework. A second survey in Spain ascertained the degree of implementation of protected area evaluation systems and the institutional interest in implementing such systems. The main weaknesses attributable to the systems presented were limited salience (for the SIAPA) and legitimacy in terms of costs (for the System for Quick Evaluation of Management in Mediterranean MPAs). However, the main reasons for the limited uptake of the evaluation systems presented were not attributable to the systems themselves, but to management or institutional limitations: the lack of basic data for and weak institutional interest in evaluation in Spain, and the scarce resources available for evaluation in the case of some Mediterranean marine protected areas.