The in vitro antioxidant properties of some new benzazole derivatives (1-10) such as benzoxazoles, benzimidazoles, and benzothiazoles were determined by their effects on the rat liver microsomal NADPH-dependent lipid peroxidation (LP) level, the scavenging of superoxide anion and the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). Compounds 1, 2, 4 and 6, showed potent scavenging effect on superoxide radical at 10(-3) M. Compound 8, 5-nitro-2-(phenoxymethyl)benzimidazole, strongly inhibited lipid peroxidation at 10(-3) M concentration.