In this study different treatment methods such as H2O2/UV, Fenton and photo-Fenton (Fe+n/H2O2/UV) treatments, have been used to investigate the removal of theMordant red 7 (MR7) azo dye fromaqueous solution. In photo-Fenton treatment, iron (Fe) powder was used as a cheap source of Fe2+ ions. Complete decolorization ofMR7 usingH2O2/UVprocess, achieved in less than 60 min. The photodegradation process was mainly effected by different parameters such as initial dye concentrations, [H2O2], pH value and presence of different inorganic salts such as carbonate, nitrate and chloride ions. The decrease in the degradation percent was in the order of Carbonate > chloride > nitrate ions. In comparison, the photo-Fenton treatment, using Feï° powder as a source of Fe2+ ions, was more efficient in the decolorization ofMR7. It was found that complete decolorization ofMR 7 obtained in about 30 min. Furthermore,mineralization ofMR 7 was investigated using chemical oxygen demand (COD) experiment. The results indicated that, 66.67%of theMR7 dye wasmineralized usingH2O2/UVprocess in a 3.0 h photoperiod. While photo-Fenton treatment (in presence of Fe0 powder), wasmore efficient and resulted in completemineralization ofMR7 dye in about 2.0 h of photoperiod.