The polarographic behavior of the monoximes and dioximes of 1,4-benzoquinone, 1,4-naphthoquinone, 1,2-naphthoquinone, and 9,10-anthraquinone has been investigated in the pH range 3 to 14. All of the compounds produce well-defined polarographic reduction waves which can be used for analytical purposes. Polarographic evidence indicates that the monoximes and the dioximes exhibit tautomerism.