Chemical composition and antimicrobial activity of the hydrodistilled essential oils from aerial parts and roots of Aster subulatus Michx. (Asteraceae) from Turkey were investigated. The essential oils of A. subulatus were analyzed by combination of GC-FID and GC-MS. Twenty-nine components comprising 79.0% of the essential oil of the roots and forty-nine components comprising 89.3% of the essential oil of the aerial parts were identified. The major constituents of the essential oil from the aerial parts were found to be elemol (21.5%), beta-eudesmol (6.3%) and caryophyllene oxide (5.2%), while the main components of the root oil were hexadecanoic (33.0%), tetradecanoic (5.3%) and octanoic (4.6%) acids. The antimicrobial activities of the oils were tested against Escherichia coli, Staphylococcus aureus and Candida albicans using a TLC-bioautography method. Both of the oils showed inhibitory activity against S. aureus and C. albicans, while the oils were found to be inactive against tested E. coli strain at 1 mg/mL concentration. This is the first report on the chemical composition and preliminary antimicrobial activity of the essential oils of A. subulatus from Turkey.