The treatment of aqueous phenol (100 mg l(-1)) and nitrobenzene (50 mg l(-1)) solutions using iron(III) and UV radiation has been carried out. The quantum yield of photodegradation of both compounds has been determined (phi(phenol) = 11.2 +/- 2.0 mmol einstein(-1), phi(NB) = 6.0 +/- 0.5 mmol einstein(-1)). The effect of the amount of ferric ion in the degradation rate has been studied in the range of molar iron(III) to organic compound ratios from 0 to 6. The reaction rate showed to follow a first-order kinetic with respect to the substrate and the kinetic constant depends on the Fe(III)/organic ratio. Optimal values of these kinetic constants have been found.