Conservation of biological diversity is one of the most important issues in conservation biology, so a wide range of quantitative spatial methods have been used to determine the biodiversity hotspots and the conservation priority areas. The main aims of the present study are determining the areas of endemism as well as the centers of diversity of the genus Onosma based on the GIE, IPAs, species richness, and AZE-like criteria approaches, to assess the status and priorities of conservation of the mentioned genus in Iran. Based on the findings of this research, centers of species richness, the main areas of endemism, top-ranked IPAs, and AZE-like criteria are situated in the Zagros ecosystems. The comparison of the four approaches used in this study shows that the IPAs and GIE techniques have succeeded in identifying the most important centers of diversity and endemism of Onosma in Iran. Considering that this genus with a high percentage of endemic species is one of the most important genera of Iranian flora and only 46 % of the IPAs and areas of endemism specified in the research are located in protected areas, identification and protection of the rest of these areas is one of the prevalent measures needed for conservation of Onosma species diversity in Iran.