In light of the growing demand for medicinal plants and their increasing significance in global society, this study examined the essential oils composition and phenolic content in the flowers and leaves of Stachys schtschegleevi. Plant samples were collected from the Jolfa region, and the essential oils were extracted using a Clevenger apparatus. The chemical composition of the essential oils was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The results showed that the percentage of essential oil in the flower organs was 39% higher than in the leaves. Analysis of the essential oils identified 61 compounds in the flowers (98.39% of the total) and 49 compounds in the leaves (98.73% of the total). The dominant compounds in the flower organs were germacrene D (20.69%), α-cadinol (9.51%), α-muurolene (7.16%), n-hexadecanoic acid (5.93%), thymol (5.41%), spathulenol (4.77%), α-pinene (4.62%) and β-pinene (4%). The dominant compounds in Pulak leaf essential oil were found to be α-pinene (12.98%), germacrene D (11.92%), α-cadinol (7.9%), thymol (6.91%), n-hexadecanoic acid (4.82%), spathulenol (4.44%) and α-muurolene (4.22%). Evaluation of the phenolic compounds showed that the total phenol and flavonoid content in the flowers (81.8 and 3.5 mg/ g of dry extract, respectively) was higher than in the leaves (56.1 and 3 mg/g of dry extract, respectively). Therefore, due to its higher essential oil percentage and greater richness in phenolic compounds, the flower organ of Stachys schtschegleevi is considered more suitable than the leaf organ for industrial applications, particularly in the field of essential oil extraction.