The present work reports on the synthesis, characterization and performance of a new cobalt(II) complex, [Co(C 10 H 21 -bim) 2 (SCN) 2 ] (bim = benzimidazole) as electrocatalyst for trichloroacetic acid and bromate reduction. Its structure was characterized by X-ray crystallography, IR spectroscopy and elemental analysis. The cobalt atom adopts a distorted tetrahedral geometry by coordinating to four nitrogen atoms from two thiocyanates and two 1-decyl-1H-benzo[d]imidazole ligands. The electrochemical behavior and electrocatalysis of the title complex bulk-modified carbon paste electrode (Co-CPE) have been studied by cyclic voltammetry. The Co-CPE shows good electrocatalytic activities toward the reduction of trichloroacetic acid and bromate. The detection limit and the sensitivity are 0.02 lM, 34.63 lA lM -1 for trichloroacetic acid detection, and 0.03 lM, 78.92 lA lM -1 for bromate detection, respectively. This modified electrode shows good reproducibility, high stability, low detection limit, technical simplicity and possibility of rapid preparation, which is important for practical application.