The association of ascorbic acid (H2A, AA) with α-tocopherol (α-T) enhances the antioxidant capability of the two vitamins in a microemulsion formed by water, pentanol and sodium dodecyl sulphate. The comparison of vitamin C oxidation kinetics in the presence and absence of α-T in the system shows that there are no tangible differences in the time of the ascorbic acid decomposition. The main effect is the enhancement of the H2A oxidation with increased pentanol concentration in the system. Ascorbic anion interacts with surfactant association structures, changing W/O microemulsion towards O/W system. The polar part of H2A is exposed to aqueous solution and subjected to oxidation.