A free radical is any species that can exist independently and contains one or more unpaired electrons. Reactive oxygen species are produced from molecular oxygen as a result of normal cellular metabolism. Superoxide anion radical, hydroxyl radical and hydrogen peroxide are species of physiological importance. The superoxide anion is formed by the addition of one electron to molecular oxygen, and the process can be catalised by xanthine oxidase. An antioxidant is a substance that delays, prevents or eliminates oxidative damage to the target molecule. The human body endogenously possesses various antioxidants to counterbalance proxidant processes. In this paper the hydrolates of selected plants were tested using xanthine/xanthine oxidase, DPPH, FRAP and Folin-Ciocalteu methods. The best antioxidant potential tested by the DPPH and FRAP method is shown by the hydrolates of plants of Juniperus communis ssp. Nana, Moltkia petraea and Mantisalca salmantica. The results are consistent with the total phenol content of the tested hydrolates. Xanthine/xanthine oxidase method at a tested concentration of 1 g/L, almost all the hydrolates show good ability to capture the superoxide anion radical. The samples show good and concentration independent ability to inhibit superoxide anion radicals. The results obtained by testing the superoxide anion trapping capability of the xanthine/xanthine oxidase method did not correlate with the results obtained by the DPPh, FRAP and Folin-Ciocalteu methods. In order to obtain relevant results by the xanthine/xanthine oxidase, it is necessary to test the ability of the hydrolates to inhibit the enzyme xanthine oxidase and to test the samples with a non-enzymatic method of trapping the superoxide anion radical.