Aq. C.l. Acid Violet 87 and C.l. Acid Orange 88, 1 g/L, were each decolorized with H2O2 0-2 or NaOCl 0-5 mg/mg dye, and 5 g/L FeCl2 as catalyst at pH 3.5. With no FeCl2, H2O2 was inactive. NaOCl decolorized promptly and FeCl2 was inadvisable. At 20 and 60degreesC, H2O2/FeCl2 decolorized in 2-5 and 1 h, resp.; NaOCl did so in 10 min at 20degreesC. Optimum H2O2 doses were 1.0 and 0.8 mg/mg dye 87 and dye 88, resp., permissible in wastewaters. Optimum NaOCl dose was 0.8 mg/mg of either dye. Decolorization rate was not affected by oxidant dose. H2O2/Fe(II) was preferred to NaOCl (in spite of its prompt reaction), because the former reduced the organic C and ChOD resp. 5-8 and 4.5 times more than did the letter.