In present work boron doped diamond (BDD) electrode was applied for studying electrochemical behavior, as well as for quantitative determination of natural alkaloid, tubocurarine (arrow poison/TUB). Electrochemical behavior was investigated using several organic solvents and aqueous buffers, at different pHs, as supporting electrolytes. After selection of the most appropriate supporting electrolyte and investigation of its electrochemical behavior, analytical procedures for quantitative analysis of TUB were developed in an acetonitrile/methanol (80:20) mixture and in 1 mol L-1 nitric acid, which had linear quantification ranges from 4 x 10(-6) to 1 x 10(-4) mol L-1 (LOD = 3.07x10(-6) mol L-1) and 4x10(-6) to 9x10(-5) mol L-1 (LOD = 2.45x10(-6) mol L-1 and 5.28x10(-7) mol L-1, depending on the selected peak), respectively. The oxidationmechanism of TUB was proposed from the theoretical aspect. Remarkable selectivity and good sensitivity were obtained after the TUB quantification method was optimized, allowing application of the developed method for TUB quantification in biological fluids, with excellent reproducibility, accuracy and precision. (C) 2019 The Electrochemical Society.