The behaviour of EDTA, ethylenediamine, iminodiacetic, 1,2-diaminocyclohexanetetraacetic, nitrilotriacetic, ethyleneglycol-bis-(2-aminoethylether)tetraacetic, diethylenetriaminepentaacetic, and triethylenetetraminehexaacetic acids was studied on a rotating platinum electrode. These substances, with the exception of ethylenediamine and iminodiacetic acid, yield anodic voltammetric waves on a platinum electrode, the heights and half-wave potentials of which are dependent upon pH and the composition of the solution. The probable mechanism of the electrode reactions is given.