Abstract The essential oils of the aerial parts of Thymus kotschyanus Boiss. et Hohen. and T. pubescens Boiss. et Kotschy ex Celak. (Labiatae) collected during the full flowering period from the suburb of Behshar (north of Iran) were isolated by hydrodistillation and analyzed by GC and GC/MS. The major components of T. kotschyanus oil were pulegone (18.7%), isomenthone (17.8%), thymol (14.9%), 1,8-cineole (9.0%), piperitenone (6.3%) and carvacrol (5.5%). The major components of T. pubescens oil were carvacrol (32.1%), thymol (19.1%), Î±-terpineol (14.6%) and p-cymene (6.1%).