Molecules acting as antioxidants capable of scavenging reactive oxygen species ( ROS) are of utmost importance in the living cell. The antioxidative properties of pyridoxine ( vitamin B-6) have recently been discovered. In this study, we have analyzed the reactivity of pyridoxine toward the ROS (OH)-O-., (OOH)-O-., and O-.(2)- at the density functional theory level ( functionals B3LYP and MPW1B95). Two reaction types have been studied as follows: addition to the aromatic ring atoms and hydrogen/proton abstraction. Our results show that (OH)-O-. is the most reactive species, while (OOH)-O-. displays low reactivity and O-.(2)- does not react at all with pyridoxine. The most exergonic reactions are those where H-. is removed from the CH2OH groups or the ring-bound OH group and range from -33 to -39 kcal/mol. The most exergonic addition reactions occur by attacking the carbon atoms bonded to nitrogen but with an energy gain of only 6 kcal/mol.