A flow injection method for the determination of the antioxidant BHT using polymer modified electrodes in connection with amperometric detection is proposed. The procedure is based on the electrochemical oxidation at 0.700 V (vs. Ag/AgCl[3M NaCl]) in phosphate buffer solution (pH 7.2). BHT is determined over the range 0.001–0.020 or 0.005–0.030 gL ¹1 . Other analytical parameters, such as electrode working potential, flow rate, electrodeposited charge and solution pH were optimized. The proposed method was applied to the determination of BHT in electrical transformer and vegetable oils samples. The results were compared with the HPLC-UV detection standard technique.