Phenols are the most abundant organochemical compounds in nature. This group of secondary plant metabolites has various roles in nature, yet the most important one is the antioxidant activity which depends on several factors. The aim of this study was to analyze mixtures of phenolic acids from subgroups of hydroxybenzoic derivatives and hydroxcinnamic acid derivatives by the ORAC method (Oxygen Radical Absorbance Activity) and to draw conclusions about possible synergistic, additive or antagonistic effect based on the results obtained. The results of this research show that most mixtures, especially mixtures of two acids, showed a synergistic effect. The addition of a third acid in the mixture in the case of hydroxbenzoic acid derivatives weakens the antioxidant activity of the mixture, but we still see a synergistic effect. While, in case of hydroxcinnamic acid derivatives, results mainly indicated both additive and antagonistic effects. In the mixtures containing four and five acids hydroxbenzoic acid derivatives mainly showed synergy, while hydroxcinnamic acid derivatives additive action. Based on this study, it can be concluded that equimolar mixtures of hydroxbenzoic acid derivatives had a better antioxidant activity and interaction effect than hydroxcinnamic acid derivatives.