The assessment of the conservation status of a species is the first step in developing a conservation strategy. IUCN Red Lists assessments are an important starting point for conservation actions and the most commonly applied method for assessing the extinction risk of a species. In this study, the global conservation status of the rock rose Helianthemum caput-felis Boiss. (Cistaceae), a perennial Mediterranean plant, was evaluated using the Red List criteria. The distribution of the species was determined by monitoring historical localities and all other suitable sites along the western Mediterranean coasts for 6 years. For each confirmed locality, the ecological and population parameters and the main threats were recorded; these data were used in a quantitative analysis of the species' extinction risk. Our findings indicate there have been several recent extinctions, and there is a continuing decline in the species' area of occurrence, habitat quality and number of reproductive plants. The main threats are related to human activities. Extinction models indicate a probability of quasi-extinction risk of c. 30% in five generations or c. 45% in three generations, with the species likely to become extinct in seven currently known localities within the next 10 years. Application of the Red List criteria indicates H. caput-felis should be categorized as Endangered. This study confirms that legal protection and passive conservation measures are insufficient to guarantee the persistence of a plant species. Active conservation and management actions are needed to protect this and other threatened species of the Mediterranean Basin.