The aim of our research was to determine whether selected essential oils (EO) exhibit antifungal activity and to determine their minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MBC). We also wanted to compare the antifungal activity of EO with that of an already established disinfectant – hydrogen peroxide. In the study we tested EO of oregano (Origanum vulgare), basil (Ocimum basilicum), sweet wormwood (Artemisia annua), lavander (Lavandula hybrida), Italian strawflower (Helichrysum italicum), rosemary (Rosmarinus officinalis), camomile (Matricaria recutita) and sage (Salvia officinalis) along with hydrogen peroxide against Candida albicans and Penicillium griseofulvum. Broth microdilution method was used to determine the antifungal activity of selected substances. To obtain the exact MIC and MBC for C. albicans we carried out the standard plate count method. To obtain the exact MIC and MBC for P. griseofulvum we inspected media with mould in microtiter plates under a magnifying lens. C. albicans was more susceptible to EO, with MIC values ranging from <0.78 to 6.25 mg/ml, in comparison with P. griseofulvum, with MIC values ranging from 3.13 to 12.5 mg/ml. The EO of oregano inhibited the growth of both fungi at the lowest concentration. Hydrogen peroxide inhibited the growth of C. albicans at a lower concentration than essential oils, while the MIC of hydrogen peroxide for P. griseofulvum was comparable to the MIC of EO of oregano. We can conclude that essential oils do exhibit antifungal activity; however, we have to consider the differences in activity of various types of essential oils and the fact that different species of fungi show different degrees of susceptibility to them. The results show that further studies of essential oils and different species of fungi could lead to the use of essential oils as a natural antimicrobial agent in food industry.