Abstract The antimicrobial activity of the steam distilled essential oil of Mentha arvensis, major isolates such as monoterpenes, menthone and isomenthone, dementholized oil (DMO), liquid menthol, l-men-thol and its acyl derivatives were studied. In vitro bioactivity evaluation of the oil, isolated components and the derivatives showed activity against a wide spectrum of human pathogenic fungi and bacteria tested. The activity of the isolated pure compounds and l-menthol derivatives was comparable to the bioactivity of original oil.