Abstract: A method for producing highly purified crystals of tetrasodium. Salt of ethylenediaminetetraacetic acid including reacting ethylene diamine, NaCN and formalin in the presence of an alkali to yield a solution containing EDTA4Na and impurities. This solution is subjected to crystallization over a solvent to form EDTA4Na crystals. The solvent is a mixture of methanol and an alcohol of either ethanol or propanol. The methanol has a ratio by weight to the alcohol of 1:0.43-4.0. The EDTA4Na crystals are then recovered after subjecting the solution to crystallization.