Background: The Mountains of the Western Lesser Caucasus with its rich plant diversity, multicultural and multilingual nature host diverse ethnobotanical knowledge related to medicinal plants. However, cross-cultural medicinal ethnobotany and patterns of plant knowledge have not yet been investigated in the region. Doing so could highlight the salient medicinal plant species and show the variations between communities. This study aimed to determine and discuss the similarities and differences of medicinal ethnobotany among people living in highland pastures on both sides of the Georgia-Turkey border., Methods: During the 2017 and 2018 summer transhumance period, 119 participants (74 in Turkey, 45 in Georgia) were interviewed with semi-structured questions. The data was structured in use-reports (URs) following the ICPC classification. Cultural Importance (CI) Index, informant consensus factor (FIC), shared/separate species-use combinations, as well as literature data were used for comparing medicinal ethnobotany of the communities., Results: One thousand five hundred six UR for 152 native wild plant species were documented. More than half of the species are in common on both sides of the border. Out of 817 species-use combinations, only 9% of the use incidences are shared between communities across the border. Around 66% of these reports had not been previously mentioned specifically in the compared literature. Only 33 species have similar use reports in both countries, most important of which are Plantago major, Urtica dioica, Picea orientalis, Anthemis spp., Sambucus ebulus, Achillea millefolium, Helichrysum rubicundum, Mentha longifolia, Pinus sylvestris var. hamata, Hypericum perforatum, Tussilago farfara, Helichrysum plicatum, Rumex crispus, Berberis vulgaris, and Origanum vulgare. More than half of species reported in each country were found to have more than one part of the plant valued for medicinal use. The most common way of using plants medicinally in both countries is drinking the water infusion of aerial parts with flowers. Based on CI index value, two-thirds of the salient 15 genera in both countries have use reports in at least seven medicinal use categories. While the most cited category with highest FIC is digestive in Georgia, it is skin category in Turkey. Patterns of medicinal plant knowledge among studied communities appear to be connected with more than one cultural factor, in particular ethnolinguistic diversity, cultural background, and access to multilingual written folk and scientific literature, or probably a combination of various factors., Conclusion: Considering the regions' floral similarity, common historical-cultural contact, and similar livelihood strategies of the communities, shared ethnomedicinal knowledge across the Georgia-Turkey border is quite low. Even though the impacts of accessing multilingual folk and scientific literature are likely to be significant, the factors that shape the medicinal plant knowledge patterns of the communities are shown to be variable among species, needing further research into intracultural diversity and socio-economical conditions, as well as the political history across the border.