The paired production of ClO2 by reduction of ClO3- and oxidation of ClO2- is achieved in a divided cell. The highly acidic nature of the catholyte and the neutral conditions at the anolyte require an intermediate compartment to prevent their interaction, since passage of H3O+ from the former to the later would chemically produce ClO2. An anionic exchange membrane, AEM/fritted glass/AEM set up was effective in preventing proton migration. The production of ClO2 was spectroelectrochemically monitored in situ and in real time at its characteristic absorption wavelength (359 nm) by adapting a normal rectangular spectrophotometer quartz cell as the electrolytic cell inside a spectrophotometer. The corresponding yields are highly dependent on the applied potential: the cathodic production is favored as the potential approaches the rest potential of the catholyte, whereas the anodic production behaves the opposite. The highest overall yield after 30 min of reaction was ca. 10%.