Thyme (Thymus vulgaris L.), family Labiateae, is fairly grown wildly throughout Iran. The essential oil of the aerial parts of T. vulgaris, cultivated in the Khorasan province, North East of Iran, was prepared. The chemical composition of the oil was identified using GC-MS. Twenty-one compounds were identified. The major components of the oil were carvacrol (57.3 %), linalool (11.8 %) and thymol (10.67 %). The amounts of the two main components, carvacrol and thymol, were compared with the results reported from other countries.