The study on perchlorate removal from simulated wastewater was carried out using a conducting copolymer poly(aniline-co-o-aminophenol) (PANOA) polymerized on multiwalled carbon nanotubes (MWNTs)-modified glassy carbon (GC) electrode. The cyclic voltammograms demonstrated that the PANOA/MWNTs GC electrode in a NaCl solution containing NaClO4 had a good redox activity, reversibility, and stability in a wide range of pHs tested (from pH <1 to 9.0). The ratio of ClO4/Cl in PANOA/MWNTs was up to 80.8%, which was 10.0% in the solution, indicating that PANOA/MWNTs had a relatively high affinity to perchlorate. The result of X-ray photoelectron spectroscopy revealed a fact that Cl ions can be strongly adsorbed on MWNTs, which resulted in an improvement in the electrical activity of PANOA and perchlorate removal. Therefore, it is possible to develop a green process for removing perchlorate from wastewater using PANOA/MWNTs. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013