Abstract A simplified pseudokinetic model to predict the mineralization evolution of organic pollutants by Fenton's reagent (FR) has been developed. The model has been validated by fitting phenol oxidation data by using FR in a batch way but could be applied to other wastewaters. The proposed model can be applied to the whole range of hydrogen peroxide dosage, values lower than those theoretically required for total mineralization or excess. To do this the model takes into account the change in the hydrogen peroxide concentration. Moreover, the model is able to explain and predict the asymptotic value obtained for mineralization of the initial TOC due to the complexation of the catalyst (iron cation) with chelating oxidation intermediates. Finally, the model can optimize the dosage of hydrogen peroxide in order to avoid the loss of this reagent.