Objective: To evaluate the essential oil composition and the antibacterial activity of an Algerian endemic plant, Launaea lanifera Pau(L. lanifera), grown in arid steppe regions.Methods: L. lanifera essential oil was isolated from aerial parts by steam distillation and its chemical composition was evaluated by gas chromatographyflame ionization detector and gas chromatography with electron impact mass spectrometry. Furthermore, its in vitro antibacterial activity against four bacterial strains was tested following the agar disk diffusion method.Results: This species had a very low essential oil yield(0.005%). Twenty-four(92.6%)individual components were identified. The main constituents were hexahydrofarnesyl acetone(31.6%),(E)-b-ionone(8.5%),(E)-b-damascenone(7.0%), 2-methyltetradecane(3.8%), n-heptadecane(3.8%), limonene(2.8%) and b-caryophyllene(2.8%). No noteworthy antimicrobial activity was observed on the tested bacteria, neither Gram negative nor Gram positive.Conclusions: This is the first report on the volatile constituents and antibacterial activity of L. lanifera. The studied essential oil does not possess significant activity against the tested microorganisms. Objective: To evaluate the essential oil composition and the antibacterial activity of an Algerian endemic plant, Launaea lanifera Pau (L. lanifera), grown in arid steppe regions. Methods: L. lanifera essential oil was isolated from aerial parts by steam distillation and its chemical composition was evaluated by gas chromatography flame ionization detector and gas chromatography with electron impact mass spectrometry. Further, its in vitro antibacterial activity against four bacterial strains was tested following the agar disk diffusion method. Results: This species had a very low essential oil yield ( The major constituents were hexahydrofarnesyl acetone (31.6%), (E) -b-ionone (8.5%), (E) -b-damascenone (7.0%), N-heptadecane (3.8%), limonene (2.8%) and b-caryophyllene (2.8%). No noteworthy antimicrobial activity was observed on the tested bacteria, neither Gram negative nor Gram positive. : is the first report on the volatile constituents and antibacterial activity of L. lanifera. The cooking essential oil does not possess significant activity against the tested microorganisms.