beta-Naphthalene sulfonic acid (beta-NSA) has been electrochemically polymerized in a mixed electrolyte of boron trifluoride diethyl etherate (BFEE) solution and trifluoroacetic acid (TFA). As-grown poly(beta-naphthalene sulfonic acid) (PNSA) is partly soluble in methanol and has a conductivity of 0.95 S cm(-1). Its structure has been examined by infrared, H-1-NMR and UV spectra. Fluorescent spectral studies indicate that the polymer is a blue light emitter with a fluorescence quantum efficiency of 4%. (C) 2003 Elsevier Science B.V. All rights reserved.