In vitro propagation of Thymus sipyleus Boiss. (Lamiaceae), an endemic from western Anatolia was investigated. Sterilized seeds of the plant were germinated on modified Murashige-Skoog medium (mMS) and Heller's nutrient media. Then, seedlings were transferred to Murashige-Skoog basal medium containing 0.4 mg/l Naphtaleneacetic acid, (NAA) and 3 mg/l Benzyladenin (BA) and then they formed callus where they were in contact with the medium. Plantlets which regenerated on the same medium formed multiple shoots within 2 weeks and they were rooted after the 4th subculture.