the reduction process of hexavalent chromium from electroplating wastewater byrnchemical precipitation in order to achieve the maximum trivalent chromium concentration.rnSodium bisulphite is one of the widely used coagulants in waste water treatment process and hasrngood reducing ability. Because of its reducing capacity, sodium bisulphite is applied to reducernhexavalent chromium from electroplating wastewater. The study has been conducted in fourrnphases. In phase one reduction of hexavalent chromium, phase two determination of hexavalentrnchromium, phase three precipitation of chromium sulphate followed by oxidation of the sludgernof Chromium (III) hydroxide. Phase one study was carried out to analyze the reduction processrnof the toxic soluble hexavalent chromium by using the concept of design experiment to justifyrnthe number of affecting factors and levels during the laboratory work followed by the syntheticrnwaste sample preparation at Homicho Ammunition Engineering Industry in Ambo.rnDifferent experiments were considered like classical method of analysis to quantify andrnqualify the wastewater sample, atomic absorption spectrophotometric technique was utilized torndetermine the amount of total chromium, and finally colorimetric method to determine thernamount of hexavalent chromium with a suitable complexing agent to engulf the ionic hexavalentrnChromium. The total numbers of experiments were fifty four (54), the first twenty seven (27) runrnwas analyzed by labeling the distributed parameters in each beaker of the solution and thernnumber of factors with their levels were indicated. For the purpose of optimization of thernselected parameters experiments were replicated, then at the second round of the experiment runrnnumber 44 was the optimized one. In order to perform these activities, the concentration of thernstock solution was 100 mg/L, and 50 ml of volume was taken to each 500 ml beaker volume withrnconcentration of 10 mg/L. With this amount phase two was conducted, to solidify the solutionrncontaining chromium sulphate Cr2 (SO4)3 generated from the redox reaction. . The requiredrnreduction time to reach equilibrium, the effectiveness of pH value for Cr (VI) reduction and thernrequired amount of sodium bisulphite to complete reduction were investigated. The redoxrnreaction was completed within 40 minutes, at pH of 2 and 50 mg/L of hexavalent chromium wasrnreacted with 200 mg/L of sodium bisulphite in deionized water.rnSodium hydroxide was used to precipitate the solution after the reaction of the precipitatingrnagent and hexavalent chromium. In Final phase oxidation of Chromium (III) hydroxide tornhexavalent chromium was carried out;rnKey words: Cr (VI) reduction, Sodium bisulphite, wastewater treatment