The oxidation of hexacyanoferrate(ll) ion by a large excess of hydrogen peroxide, in slightly acidic aqueous media containing potassium dihydrogen phosphate (pH 5.10 ± 0.05), was followed by monitoring the increase of absorbance at 420 nm as the colorless Fe(ll) complex gradually evolved into the yellow Fe(lll) complex. The reaction was inhibited by OHcontaining organic compounds, either alcohols or carbohydrates, and two different inhibition pathways were observed, an iron(III)-independent pathway (rate constant k1) and an iron(III)mediated pathway (rate constant k2). A BASIC-language computer program was developed in order to use the fourth-order Runge-Kutta integration method to obtain the concentrations of the Fe(ll)-inhibitor complex and the Fe(lll) reaction product. Rate constant k1, whose value is determined by that of the initial rate, decreased slightly as the concentration of alcohol / carbohydrate increased, and a mechanism involving the formation of hydroxyl radicals in a Fenton-like reaction and its posterior scavenging by the organic antioxidant additive has been proposed. Of the 8 inhibiting agents that were tried, the most potent antioxidant under the experimental conditions of this study was D-mannitol. Rate constant k2, whose value is a measurement of the deviation from a pseudo-first order behavior provoked by the inhibiting agent, increased notably as the concentration of the latter increased, and a mechanism involving the complexation of the Fe(lll) product by the organic inhibitor and its posterior outer-sphere one electron reduction from hexacyanoferrate(ll) ion has also been proposed. This might result in a blockage of the regeneration of pentacyanoaquaferrate(ll) ion, an intermediate believed to be essential for the redox reaction to take place. KeywordsCarbohydrates • Hexacyanoferrate(II) ion • Hydrogen peroxide • Hydroxyl radical intermediate • Inhibition• Polyalcohols