In the current investigation, the electrochemical oxidation of caffeic acid (CA) in the absence and presence of 1,4-benzenediboronic acid (BDA) was studied. The voltammetric study indicates that CA (1) oxidized to its o-benzoquinone (1ox) within a two-electron process. In basic pHs, the electrochemically generated 1ox is unstable and participates in the dimerization reaction. The results indicate that BDA reacts with CA, and a complex is produced. By the use of cyclic voltammetry, the electrochemical behavior of CA–BDA complex has been studied in aqueous solution. It was found that the electrochemical mechanism of the produced CA–BDA complex is CEC. Also, the electrochemical study of the CA–BDA complex was studied in the presence of glucose. The results show that the tendency of BDA to form the complex with CA decreases due to the addition of glucose, and the anodic peak of CA–BDA complex decreases with the increasing concentration of glucose.