This paper presents a new photo-Fenton procedure applied in oxidative degradation of organic pollutants using 4-chlorophenol (4-CP) as low biodegradable testing compound. The homogeneous photo-Fenton process was modified by using a photo-catalytic reactor equipped with a steel wire mesh which acts as source for Fe2+ catalyst generation into reaction medium and as heterogeneous catalyst, by iron oxy-hydroxyl compounds formation on the surface. The oxidation process was evaluated by measuring the organic substrate concentration changes using COD, TOC, HPLC and LC-MS analyses, in correlation with modification of solution pH and Fe2+/3+ concentration as function of reaction time. The oxidation rate is higher at the beginning of the process and then slows down, being controlled by the nature of the intermediate oxidation products and by the change of Fe(III)/Fe(II) molar ratio into the solution. The new photo-Fenton procedure is simple but effective, combining the advantages of homogeneous and heterogeneous photo-Fenton processes.