For antiinfectious fight, Aromatic and Medicinal Plants, constitute resources to valorize. Six germs belonging to Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae frequently encountered in hospital have been selected to assess antibacterial activity of Lavandula abrialis, Lavandula dentata L and Lavandula pedunculata Mill. Essential Oils (EO). EOs obtained by hydrodistillation were analyzed by Gas Chromatography/Mass Spectrometry and their antibacterial activity was assessed through discs-diffusion tests. EOs analyses revealed monoterpenes-rich oils. Camphor (49.75%) and 1.8 cineole (39.84%) were found in L. dentata EO while camphor (46.36%) ,fenchone (13.19%) and ?-pinene(10.74%) were observed in L. pedunculata. Linalool (25%), camphor (16.06%), linalool acetate (13.66%) and borneol (11.94%) were the main components in L. abrialis. Biological tests proved EOs' antibacterial power against germs despite resistance to Beta-lactamin antibiotics. The highest inhibition was obtained with L. pedunculata EO.