ABSTRACT. The electrochemical behavior of nicotine was investigated using cyclic and square wave voltammetric techniques. Electrochemical activation of glassy carbon electrode significantly increased the oxidation peak current of nicotine compared to the bare glassy carbon. At the activated glassy carbon electrode, the square wave voltammetry of nicotine revealed an oxidation peak at +838 mV (vs. SCE) in phosphate buffer solution of pH 7. Under optimized conditions, the linear range (R 2 = 0.998) and detection limit (3σ) for nicotine determination were found to be 1-200 µM and 0.7 µM, respectively. The method was successfully applied for the determination of nicotine in two brands of commercial cigarettes and acceptable recovery values of 97-108% were found.