A composite polymer surface on a tine oxide offers dramatic improvement in the stability and sensitivity of voltammetric measurement of pyridostigmine bromide as compared to individual tin oxide, polyaniline or polypyrrole coated electrode. A linear current response was achieved with a detection limit of 1x10(-6) M. The stability and morphology of the polymer surfaces were determined by thermogravimetry and scanning electron microscopy respectively. The results suggest that composite polymer electrode is the best detector for pyridostigmine bromine (PB) at lower concentration.