The kinetics of the oxidation hexacyanoferrate(II) with chloramine has been investigated spectrophotometrically at 25.0-degrees-C in buffered aqueous solution at pH 8.5-9.50. Reaction docs not show significant dependence on [Fe(CN)6(3)] in the reaction of [Fe(CN)6]4- with a large excess of chloramine solution, but it does show in the reaction of [Fe(CN)6]4- with a similar concentration of chloramine. With chloramine in excess, the rate as given by -d/dt [Fe(II)] = k(obs)[Fe(II)]. The result obtained is interpreted in terms of a reaction mechanism in which the first stage, Fe(II) + NH2Cl --> Fe(III) + degrees-Cl, can occur by an irreversible or reversible process.