In general, the optimization problems contain more than one response, which often conflicts with each other. This paper proposes the TOPSIS-based Taguchi optimization approach to determine the optimization of reverse osmosis process parameters for improving recovery and quality of permeate. The performance criteria are identified for Permeate are COD, Total Solids, Conductivity and Hardness in reverse osmosis process. They are dependent on process parameters Operating Pressure (OP), Potential Hydrogen, Oxidation Reduction Potential and Anti-Scaling Agent. Four factors having three control levels and one factor having three control levels are identified for performance criteria. The temperature is taken as noise factor. The data for permeate, recovery, and quality of permeate obtained by running scenario that combines factor levels in Taguchi design while the signal to noise (S/N) ratios are calculated for the data. After a decision matrix is generated by the S/N ratios, the TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) method is then used to transform the multi-response problem into a single- response problem. The anticipated improvement rate is also determined by finding the levels of the factors in order to optimize the system which uses Taguchi I’s single response optimization methodology.