This work evaluates the antioxidant potential of acetyl and nitro derivatives of eugenol through computational techniques. Structural analysis and Hydrogen Atomic Transfer (HAT) antioxidant mechanism were investigated by density functional theory (DFT). Each molecular structure was optimized by the hybrid functional M06-2X with a basis set 6-31+G(d,p), and the HAT mechanism with HO, HOO, CH3O, DPPH radicals was evaluated. In agreement with experimental data from previous studies, two steps of hydrogen transfer were tested. Thermodynamic data showed the need for two stages of hydrogen transfer, followed by the formation of quinones to make the reaction with DPPH spontaneous. Theoretical kinetic data showed that the preferred antioxidant site depends on the instability of the attacking radical and confirmed the antioxidant profile of eugenol (E1) and 5-allyl-3-nitrobenzene-1,2-diol (E5) in the DPPH test. This study shows that the 4-allyl-2-methoxy-(4-nitrophenol) (E4) structure also has an anti-radical activity that is not seen in the experimental due to chemoselectivity of DPPH.