Carabus hungaricus Fabricius, 1792 (Coleoptera: Carabidae) is a Natura 2000 species, protected by Directive 92/43/EEC (Annexes II and IV) and included in the Berne Convention (II) and CORINE. It is declining everywhere across its highly fragmented distribution range (from Central Europe to Eastern Siberia), sharing the fate of the temperate grasslands that it lives in, which are among the most threatened biomes on Earth. In Bulgaria, it is protected by the Biological Diversity Act (Annexes II and III), added in the Bulgarian Red Data Book as “Vulnerable”, and included in the standard form of only one protected area (BG0000322 “Dragoman”) with an unfavourable status. This study presents a part of the results from the work on the development of an Action Plan for its conservation in Bulgaria. During the three-year study (May 2021–December 2023), using 252 pitfall traps, we explored 42 plots in central–western Bulgaria. We proved the strong attachment of the species to the karst steppes, and its requirement for a lack of anthropogenic pressure or changes in the landscape structure, vegetation, edaphotope, and microclimatic characteristics. In the developed Action Plan, for the period of 2023–2032, restrictive measures related to the conservation of the old and newly established localities and the use of traditional extensive practices maintaining the karst steppe biome in an unchanged state, ensuring the existence of the entire steppe biota, were established. All localities of Carabus hungaricus in Bulgaria are situated in the karst steppes of the small mountains around the Sofia Basin. Since they represent the southernmost areas of the entire Eurasian steppe biome, the existence of the entire steppe complex in this border refugium is highly vulnerable and dependent on full conservation, which can only be achieved by designating strictly protected areas.