Salvia mirzayanii Rech. F. & Esfand. is one of the medicinal species of the Lamiaceae family, growing wild only in Iran. In this study, different plant organs (leaf, flower, stem and whole plant (=aerial parts)) were collected from the Khonj region of Fars province in March 2018 and studied for their essential oil content and chemical composition. The essential oil of samples was extracted by hydro-distillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The essential oil yield of leaf, flower, stem and aerial parts was obtained to be 3. 2, 2. 6, 0. 4 and 2. 3% (w/w), respectively. The highest number of identified chemical components was observed in aerial parts and flowers (26 compounds) and the least in stem (23 compounds). The results of essential oil compound analysis revealed that α-terpinyl acetate, linalool, 1, 8-cineol, β-eudesmol, δ-cadinene, and α-terpineol were the main compounds in the leaf essential oil. The main compounds of flower essential oil were included δ-cadinene, α-terpinyl acetate, linalool, β-eudesmol, and γ-cadinene. Compounds α-terpinyl acetate, linalool, linalool acetate, 1, 8-cineol, and α-terpineol were abundantly found in the stem essential oil. The main compounds in the essential oil of aerial parts were δ-cadinene, α-terpinyl acetate, linalool, 1, 8-cineol, γ-cadinene, and α-terpineol. The presence of chemical diversity in the essential oil of the whole plant and its various organs could be considered for pharmaceutical, food and cosmetic industries as well as for the plant breeders in selecting the appropriate organs for consumption and breeding purposes.