The electroreduction of the pyridine-4-aldoxime is revisited and its four-electron exchange process is analysed by means of classical polarography, differential pulse polarography, linear cyclic voltammetry, exhaustive electrolysis and W-visible spectroscopy on a wide pH interval covering the four acid-base species of the oxime. The acid-base properties of both oxime and its four electron reduction product are characterized in buffered aqueous solution. From polarographic and voltammetric parameters, the electrode process is analysed in different pH intervals, in particular, the process causing the first-wave which corresponds to the electroreduction of the conjugate acid and free base oxime. The observation of a second two-electron process at more negative potentials and the comparison with the electrochemical behaviour of the imine derived from pyridine-4-aldehyde and n-hexylamine and the proper pyridine-4-aldehyde are discussed in dealing with the four electron process.