Oxidative treatments of benzothiazole and benzothiazole derivatives (2-mercaptobenzothiazole, 2-hydroxybenzothiazole) in aqueous solution have been studied by using H2O2/UV and iron(III) photoassisted Fenton techniques. Experimental runs have been carried out in the pH range 3.0-8.0 by means of annular reactors and proper UV lamps. The effect of pH, the initial concentration of hydrogen peroxide, the substrate, and the iron(III) concentrations have been investigated. A suitable model has been developed and used for the best estimation of kinetic constants for HO radical attack on the target molecules with the H2O2/UV system. The values obtained with this model are consistent with those reported in the literature for other heterocyclic compounds.