Poly(o-aminophenol) (POAP) synthesized in acid medium is a ladder polymer whose redox reaction was considered as an internal conversion between oxidized and reduced units.1 The redox conversion of POAP must be accompanied by the proton exchange between the polymer and the solution. Despite a great number of studies reported in the literature about POAP synthesized in acidic media, there is relatively little work that has been reported about the electrochemistry of POAP in neutral and alkaline solutions.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas