Short-tooth sage (Salvia brachyodon Vandas) belongs to the genus Salvia, section Salvia. This species is one of the rarest species of the Dinaric karst. Only two localities have been confirmed at the present time: Mt. Sveti Ilija on the peninsula of Pelješac (Republic of Croatia) and 150 km southeast of Mt Orijen (Republic of Bosnia and Herzegovina and Republic of Montenegro). The aim of this graduation thesis was to determine morphological diversity of short-tooth sage using morphological measurements and statistical methods. The analysis of variance (ANOVA), correlation, Principal Component Analysis (PCA) and Discriminate Analysis were performed using SAS computer program. The morphological analysis based on 16 morphological characters showed that two populations are especially different in four morphological traits: inflorescence length, glandular sessile trichome on a flower pedicel, calyx length and calyx appendices length. Differences in morphological traits may be explained as the adaptation of plants to different habitat conditions present at these two localities. Information on the morphological diversity of short-tooth sage populations together with the previously established genetic parameters represent a significant contribution to solving the complex phylogenetic and taxonomic relationships within sections Salvia, but also contribute to better protection of these rare and endangered species.