A simple and rapid procedure was developed for the direct measurement of the antioxidant capacity of cereals. It entails grinding of cereals, mixing with 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) reagent, centrifugation and measure of the absorbance. The ABTS reagent was dissolved in a mixture of ethanol:water (50:50, v/v), instead of 100% ethanol, in order to overcome low solubility of water-soluble antioxidant compounds of some cereals. A reaction time of 30 min allowed plateau values to be reached during the antioxidant capacity measurement of cereal samples. The accuracy of the direct procedure was confirmed by measuring, in solid state, the antioxidant activity of pure phenolic compounds.