The objective of the research study was to determine the biological activity of essential oil and extract made from ‘Asia’ peppermint cultivar and to determine the volatile compounds therein using a GC/MS method. The research material constituted the ‘Asia’ cultivar of peppermint herb (Mentha piperita L.) originating from an experimental farm. The essential oil was produced by hydrodistillation using a Deryng apparatus, and the alcoholic extract by maceration. It was found that the essential oil and the extract from peppermint showed different chemical compositions. In the essential oil, 45 compounds were identified, whereas in the extract: 15. The essential oil was characterized by the highest percent content of menthol (24.2 %), isomenthon (11.6 %), isomenthol (7.9 %), eucalyptol (6.1 %), and menthyl acetate (5.8 %). In the peppermint extract, the following compounds prevailed: menthol (34.4 %), isomenthone (17.8 %), and neoisomenthol (7.1 %). Furthermore, the metabolic precursor of sterols, squalene, was determined in the peppermint extract, as were phytol and stigmast 8(14)-en-3β-ol. A disc-diffusion method was applied to assess the antibacterial and antifungal activity. The analyses proved that the bacteria were less sensitive to the peppermint essential oil than the fungi and the extract did not show any antifungal activity.