Using electronic absorption spectra and thin layer chromatography, the reaction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) with O-2(center dot-), HO center dot, HO-, and HOO- anions and free radicals revealed the formation of the para-nitro- and para-hydroxy-derivatives of 2,2-diphenyl- 1-picrylhydrazine (DPPH-H) and of DPPH fragmentation products ( diphenylamine, tetraphenylhydrazine). The reaction of DPPH with the O-2(center dot-) anion-radical ( from KO2 in benzene solution at room temperature in the presence of 18-crown-6 ether) is pseudo-first-order during the first 25 minutes.