Visible light-assisted photo-Fenton-like oxidation of a mono-azo textile dye. acid red 88 (AR88), has been carried Out in the presence of Co2+ as the catalyst and peroxomonosulphate (PMS) as the oxidant. Decolorization of AR88 in the Co2+/PMS system was observed to follow zero-order kinetics with respect to the dye. It was also found that the decolorization of AR88 increased as the concentration of cobalt ions was increased. The rate of abatement of the acid red 88 was found to be independent of the concentrations of dye and oxidant (PMS). Mineralization studies were also carried out by monitoring the reduction in total organic carbon (TOC) content during the course of the reaction and a suitable mechanism has been proposed. (C) 2009 Elsevier B.V. All rights reserved.