The redox behavior of a menadiol derivative, 4-hydroxy-5-methoxynaphthalene-1-yl acetate (HMNA) was investigated in a wide pH range by using modern electrochemical techniques. The techniques utilized in this study were cyclic voltammetry, square wave voltammetry and differential pulse voltammetry (CV, SWV and DPV). A sharp anodic signal in the forward scan followed by a cathodic peak (associated with the reduction of the oxidation product of HMNA) in the reverse scan produced a counter oxidation signal in the positive realm of glassy carbon electrode. Physical parameters like diffusion coefficient and heterogeneous electron transfer rate constant were determined from scan rate and concentration effects. Square wave voltammetry evidenced the quasi-reversible nature of the electrochemical process. The involvement of protons in the redox mechanism was determined from the peak potential shift as a function of pH. The redox mechanism of HMNA proposed on the basis of CV, SWV and DPV results was supported by theoretical calculations. Moreover, a detailed UV-vis spectroscopy was carried out in a wide pH range for characterization and pK(a) determination of HMNA. (C) 2012 Elsevier Ltd. All rights reserved.