Essential oil from flowers, stems, and roots of Eremostachys laevigata Bunge. gathered in Iran was analyzed using gas chromatography (GC) and gas chromatography/mass spectroscopy (GC/MS), and 23, 21, and 9 compounds were identified, respectively. The primary components of all three oils were found to be 1,8-cineole, benzaldehyde, and piperitenone oxide: 18.3%, 18.7%, and 2.5%; 17.9%, 7.7%, and 63.3%; and 15.7%, 21.3%, and 1.2%, respectively. The oils derived from flowers and stems also contained cis-piperitone oxide as a major component (10.1% and 12.2%, respectively). E. laevigata oil showed antibacterial activity, particularly towards Gram-positive bacteria; additionally antioxidant activity was induced with IC(50) of flowers, stems and roots of E. laevigata (277.1, 495.0, and 212.6 μg/ml), respectively. Furthermore, under β-carotene-linoleic acid test assay the flower, stem, and root oils of E. laevigata had a high antibacterial effect.