The terpenoid composition of steam volatile oil obtained from the aerial parts of Scutellaria repens Buch-Ham. ex D. Don (Lamiaceae) was analyzed by gas chromatography (GC) and GCâmass spectrometry (GCâMS). The oil was found to be rich in sesquiterpene hydrocarbons (77.5%); aromadendrene (30.7%) and Î²-funebrene (15.0%) were the principal constituents. Forty-four components were identified representing 90.8% of the oil. Antibacterial activity of the oil against ten bacterial strains was determined by measuring the inhibitory zone. The oil showed significant activity against Escherichia coli, Enterococcus faecalis and Klebsiella pneumoniae.