We analysed the status and distribution of the Sage Skipper Muschampia proto (Ochsenheimer, 1808), a rather rare and local Hesperiidae species at the edge of its range in the north-western part of the Balkan peninsula, mainly Croatia and Bosnia & Herzegovina. In order to determine the species' presence in the region, we mapped the occurrence of its hostplant, Jerusalem Sage Phlomis fruticosa Linnaeus (Lamiaceae). We also summarized all the available knowledge on M. proto in the Balkan Peninsula and provided a literature overview for each country this species has been recorded in so far. In Croatia, the distribution of M. proto is very limited and is located only in the wider surroundings of Dubrovnik city. In the present paper, we also provide the first and only record of M. proto in Bosnia & Herzegovina, from a single locality close to the Croatian border in the Dubrovnik area. Due to its limited distribution in both countries, we propose that the conservation status of the species should be changed from none to vulnerable.