The analysis of the essential oil of Lasiocephalus longipenicillatus by GC-MS, yielded α-pinene (48.3%), α-humulene (15.8%) and germacrene-D (15.5%) as major constituents. The essential oil showed a strong antibacterial activity against important human pathogenic bacteria, such as Staphylococcus aureus and Enterococcus faecalis.