The composition and antimicrobial activity of the essential oil from the underground parts (roots and rhizomes) of Laserpitium zernyi Hayek (Apiaceae) were investigated. The pale blue essential oil, obtained by hydrodistillation, was analyzed by GC and GC-MS. Forty-three compounds were identified (94.3% of total oil). The main constituent, beside alpha-pinene (31.6%) was alpha-bisabolol (30.9%), so this oil may be a novel potential natural source of this sesquiterpene alcohol. The antimicrobial activity was tested using the microdilution method against Gram (+) bacteria (Staphylococcus aureus, S. epidermidis, Micrococcus luteus, Enterococcus faecalis), Gram (-) bacteria (Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli), and two strains of yeast (Candida albicans). L. zernyi oil showed significant antibacterial activity against S. epidermidis, S. aureus and M. luteus, but lower activities against the other tested strains.