This study reports the results obtained for the degradation of humic acid (HA) in aqueous solution, by electrochemical and photoelectrochemical oxidation. The experiments were carried out using electrolysis and photo-assisted electrolysis on a thermally prepared oxide electrode mounted in a flow cell reactor. Results showed that both process are effective for the degradation of humic acid. However, by assisting electrolysis with UV radiation, the total organic carbon (TOC) reduction rate was greatly improved. For instance, at 20 mA cm(-2), electrolysis was responsible for 25% of TOC reduction after 180 min of reaction time. On the other hand, the decrease during the photoelectrolysis reached 65% at the same current density and processing time. (c) 2004 Elsevier B.V. All rights reserved.