Surface-enhanced Raman scattering (SERS) spectra and cyclic voltammetry were used to detect the products of the oxidation and reduction of p-aminoazobenzene (PAAB) on roughened gold and silver electrodes in acidic and neutral solutions. The results indicated that oligomerization products are formed during the oxidation of PAAB on a gold electrode. We identified these products as oligomers formed by C-N coupling of the PAAB cation radicals. The same products are formed on a silver electrode at a lower potential as the result of a photoelectrochemical reaction. The measurements carried out in the negative potential range proved that PAAB undergoes irreversible reduction in acidic media and reversible reduction to hydrazobenzene in neutral media.