Abstract: A method for measuring the uranium concentration of an aqueous solution including the following successive steps: a) electrochemical reduction towards valence IV, of the uranium present in the aqueous solution with a valence greater than IV, this reduction being implemented at pH<2 and by passing an electrical current in the solution; b) measurement of the absorbance of the solution obtained on completion of step a) at a chosen wavelength between 640 and 660 nm, and preferably 652 nm; and c) determination of the uranium concentration of the aqueous solution by deduction of the uranium concentration of valence (IV) present in the aqueous solution obtained on completion of step a) from measurement of the absorbance obtained in step b).