The electropolymerization of phenol and chlorinated phenols (monochlorophenols, dichlorophenols, 2,3,6-, 2,4,6-, 2,4,5-trichlorophenols and pentachlorophenol) was studied on a platinum electrode at 0.78 V vs SHE in alkaline 1 M NaOH aqueous solutions containing 0.1 M of the phenols. The low molecular weight reaction products were investigated by means of gas chromatography mass spectrometry (GCMS). Product analyses show that oligomers (dimers, trimers and tetramers) are present in the polymer mixtures formed. The MS spectra reveal the ether-linked nature of the oligomers formed during the electrooxidation-electropolymerization of the phenolic compounds. The mass spectra of the low molecular weight substances formed suggest that the oxidation-polymerization of phenols proceeds following two different mechanisms: (i) through the quinol-ether route (without chlorine elimination) and (ii) via the nucleophilic-radical substitution (S(RN)1) route (with some elimination of chlorine from ortho and/or para positions).