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A new method for monitoring the relative activity of antioxidants is presented, and its advantages and limits are discussed. The method is based on the previously reported inhibitory effects of free-radical scavengers on the oscillations of the Briggs-Rauscher reaction. The effect consists of an immediate cessation of oscillations, an inhibition time that linearly depends on the concentration of the antioxidant added, and subsequent regeneration of oscillations. Here the effects of ten antioxidants (pyrocatechol ( benzene-1,2-diol), ferulic acid ( 3-(4-hydroxy-3-methoxyphenyl)prop-2-enoic acid), caffeic acid ( 3-(3,4-dihydroxyphenyl)prop-2-enoic acid), 2,6-, 3,4-, 2,4-, 3,5-, and 2,5-dihydroxybenzoic acids, homovanillic acid ( 4-hydroxy-3-methoxybenzeneacetic acid), and resorcinol ( benzene-1,3-diol)) were studied in detail. Relative antioxidant activities of these substances with respect to resorcinol were determined in different ways on the basis of inhibition times. The limits of the calculated values of relative activity based on the Briggs-Rauscher reaction are the same as those obtained with other analytical procedures and are discussed here. The new method is inexpensive: reagents and apparatus are commonly used in all chemical laboratories. The thermochemical behavior of the Briggs-Rauscher reaction and the dependence of inhibition time on the temperature were also carefully investigated and taken into account. A semiquantitative mechanistic interpretation of the inhibitory effects based on a suitable kinetic model is given.