Chromone (4H-chromen-4-one, 4H-1-benzopyran-4-one) and related compounds are important pharmacophores and privileged structures in medicinal chemistry because of their important biological activities such as anti-tumor, anti-HIV, and antioxidant. In the study, the density functional theory (DFT) calculations were performed for radical scavenging activity evaluation of a series of 3-styrylchromone derivatives. The reaction enthalpies related to the steps in the radical scavenging action mechanisms and several physicochemical descriptors such as global hardness, softness, and electronegativity were computed in gas phase and in water. The solvation effect of water on the antioxidant activity was taken into account by using the conductor-like polarizable continuum model. The calculated results were discussed by considering all physicochemical properties of molecules: thermodynamic, orbital, and structural. The results obtained were consistent with the experimental results.