The electrochemical behavior of zirconium and boron and the synthesis of disperse zirconium diboride powders and coatings from the chloride-fluoride melts have been studied by voltammetry, galvanic and potentiostatic electrolysis, and X-ray phase analysis. It has been shown that the electrochemical reduction of Zr in the chloride-fluoride melts has the different mechanisms for the low and high concentration of the fluoride ion in the melt. In the first case, it proceeds according to the scheme of auto-inhibition; in the second case, the 4-electron reverse one-stage discharge process is observed. By adjusting the ratio [F-]: [Zr(IV ) ] in the melt, it is possible to find the conditions for the implementation of the one-stage 4-electron discharge process of zirconium and its diboride. During the electrometallurgical synthesis of ZrB2, the electro-active particles that formed as a result of the chemical interaction of zirconium- and boron-containing particles and that have different compositions than those formed in the partial zirconium- and boron-containing melts are discharged.