In the technologies of creation of preparations with plant protective effect against patho-genic agents, ecologically harmless, it is of great importance to identify the sources of plant raw material of compounds with antimicrobial effect, the development of isolation systems of compounds and the screening of their activity. Higher plants produce hundreds of thousands of different compounds with important biologi-cal, pharmacological and ecological roles that often present a safe way to defend against herbivo-rous insects, phytopathogenic microorganisms, causative agents of human diseases. In connection with this, crude plant extracts, purified and fractionally directed, are successfully used to create active principles with desired properties. It is estimated that there are about 2.5 million higher plant species, most of which have not yet been examined for their biological activities [4]. Some constituents of tea, especially green tea such as epigallocatechin gallate, epicate-chingallate, epigallocatechin and epicatechin are powerful antioxidants that help increase the body’s immunity. Data on the antibacterial activity (Escherichia coli, Listeria monocytogenes) of tea extracts are known, including green tea [1, 2]. Therefore, research in the field of identification and study of plant raw materials – sour-ces of bioactive compounds with curative and phytosanitary potential, are undeniably current, timely and of a major importance. Purpose: The aim of this research was to establish the antimicrobial activities of oxidized tannins isolated from black tea leaves, commercial green tea and pomegranate peels.