The polarographic behavior of some organic dyes such as nitro-benzo-triazol, amino-nitro-benzo-triazol, benzo-triazol azo thionaphthene carboxylic acid and 5-methyl imidazol 2-methyl benzo-triazol in aqueous buffered media has been studied. The results reveal that the reduction reactions occurred irreversibly under diffusion-control. The reduction mechanism of nitro-benzo-triazol and amino-nitro-benzo-triazol involve the consumption of six electrons in the form of one wave in acid and two waves in alkaline media. The electro-reduction of benzo-triazol azo thionsphthene carboxylic acid consumes four electrons. The mechanism proposed for that compound indicates that the triazol centre forms a radical as an intermediate state in alkaline medium. The reduction process of 5-methyl imidazole 2-methyl benzo-triazol contains two consumed electronic in acid media while four electrons are consumed in alkaline media.