The paper reports the composition of the essential oil from aerial parts (leaves) of Stachys byzantina (Lamiaceae) from North-West of Iran. The essential oil was extracted by hydrodistillation from selected plants and its chemical composition was determined by GC-MS system. The mass fraction of oil on dry weight base was 0.4 %. Altogether, 21 compounds were identified corresponding to 87.9 % of the total oil. The main components were germacrene D (9.6 %), Menthone (6.9 %), 1,8-cineole (14.8 %), Î±-terpineol (7.8 %), cubenol (9.9 %), Î±-cadinol (6.8 %) and Linalool (12.9 %).