Phenolic compounds are a large group of aromatic compounds. In plants, they occur as secondary metabolites, and in the plant cell they are represented as soluble-free and insoluble-bound molecules that play a significant role in the plant's defense mechanisms against plant pathogens, as phytoanticipins and phytoalexins. The goal of the work is to collect and present modern scientific knowledge about phenolic compounds in plants and their role in defense mechanisms against plant pathogens, as well as the possibilities of developing new, ecologically harmless plant protection strategies by modifying their phenolic profile. Based on a review of modern scientific literature, the role of phenolic compounds in plant defense against pathogens will be shown by describing different groups of phenolic compounds synthesized by cultivated plants, by describing their biosynthesis in the plant cell, and by describing the functioning of different phenolic compounds as phytoanticipin and phytoalexin in the plant cell. Also, the possibility of developing new, ecologically harmless plant protection strategies will be shown by describing the way of modifying the phenolic profile of plants and the consequent effect on the resistance of plants to the attack of plant pathogens.