3,4-Dihydroxybenzaldehyde has been recognized as one of the antifungal compound extracted from the outer skin of green Cavendish bananas. It can be synthesized from catechol via Fries rearrangement. 3,4-Dihydroxybenzaldehyde is reported as bioactive compound which inhibits the H2O2-induced apoptosis of granulosa cells. Oxidation of 3,4-dihydroxybenzaldehyde on glassy carbon electrodes is reported to afford stable redox-active electropolymerized films containing a quinone moity.