The traditional Japanese beverage amazake was evaluated as a possible treatment for oxidative stress. For this purpose, the radical scavenging activities of four kinds of amazake were investigated by determining diphenylpicrylhydrazyl radical, galvinoxyl radical and superoxide anion radical quenching activities using a spectrophotometric method and an electron spin resonance (ESR) technique. ESR measurements were used to assess the superoxide anion radical scavenging activity by employing dimethylpyrroline N-oxide as a spin trapping reagent. The ferricyanide-reducing activity and chelating activity were evaluated spectroscopically. The results indicated that amazake made from brown rice had stronger radical scavenging, metal chelating and metal reducing activities than amazake produced from white rice and sake cake (by-product of sake).