Strong anthiseptic activity of essential oils has been known for many centuries. The volatile or essential oils – aetherolea are secondary plant metabolites containing different compounds. A large number of essential oils and their constituents have been investigated for their microbial properties against some bacteria, fungi, viruses and protozoa. Their antimicrobial activity is strictly connected to chemical composition. So far there have been no reports on growing resistance of bacterial and fungal strains to constituents of oils. Various essential oils produce pharmacological effect demonstrating anti-inflammatory, analgesic and antioxidant properties. Essential oils of tea tree, thyme, oregano, savoury, basil, sage, clove, cinnamon were found to possess the strongest antifungal properties. The highest activity was reported for phenols – thymol, carvacrol and eugenol. These are thyme, oregano and savoury oils containing thymol and carvacrol as well as clove and cinnamon leaf oils containing eugenol. One of the most effective essential oil is Melaleuca alternifolia oil. Tea tree oil showed high activity against Candida sp., Trichophyton sp. and Microsporumsp. Thyme, oregano and rosemary oils appeared to have a wide spectrum of antibiotic activity against Candida albicans, Trichophyton sp., Epidermophyton floccosum and Microsporum canis. Clove oil and cinnamon leaf oil showed significant growth inhibition of Aspergillus flavus, Aspergillus parasiticus, Candida albicans and Cryptococcus neoformans. Volatile oils and volatile oils compounds have been shown the strong immunostimulatory effect – Pini Oil, Citri Oil, Geraniae Oil and a-pinen. Essential oils are frequently used in dermatology, especially in fungal infections. With good results oils are use in gynaecology and respiratory tract infections.