Relevance. The use of chemical fungicides in protecting plants from pathogens is the most common way, despite the proven danger of pesticides. The use of biofungicides based on essential oils of medicinal plants, which also have phytoncidal properties, can be a suitable alternative to chemical preparations. In the years favorable for the development of alternariosis or cladosporiosis, spots appear on the plants, leading to necrosis and significant loss of seed productivity. Therefore, the search for new effective and safe means of combating fungal phytopathogens becomes relevant.Methods. Alternaria alternata (2018-1.1) and Cladosporium cladosporioides (2019-11.4) strains were isolated from leaves with signs of alternariosis and cladosporiosis, on which the essential oils Abies alba, Artemisia vulgaris, Caryophyllus aromaticus, Coriandrum sativum, Lavandula officinalis, Ocimum basilicum, Pimpinella anisum, Rosmarinus officinalis, Salvia sclarea, Thymus vulgaris. The antifungal activity of essential oils was evaluated by comparing the diameter of the experimental (with the addition of essential oil to the Petri dish) and control colonies using the author’s scale.Results. All studied essential oils had antifungal properties, but species-specificity was observed. Essential oils of basil, coriander and thyme showed a fungicidal effect on C. cladosporioides and A. alternata. Lavender oil proved to be a fungicide for A. alternata and a strong fungistatic for C. cladosporioides. To create biological products for plant protection against alternariosis, sage essential oil (moderate fungistatic effect) may also be of interest, and cladosporiosis - anise and rosemary oils.