Objectives: To find the suitable solvent for the oxidation of methionine by Cr(VI) reagents using EDAS and TOPSIS method. Methods: When methionine oxidized by Cr(VI) complexes i.e. tetrakis(pyridine)silver dichromate (TPSD), quinolinium bromochromate (QBC), tetraethylammonium chlorochromate (TEACC) and quonilinium chlorochromate (QCC) formation of corresponding sulfoxide take place. Reaction performed in chloroform (CF), 1,2dichloroethane (DCE), dichloromethane (DCM), dimethylsulphoxide (DMSO) and acetone solvents. Findings: Reaction is fastest in DMSO and slowest in acetone for the oxidation of methionine in the following-DMSO, DCE, DCM, acetone, CF. Novelty: Solvent effect is investigated using the rate constant k 2, by EDAS and TOPSIS methods.