The hexachlorozirconates of sodium and potassium have been produced in a closed system following the reaction:[Formula: see text]where M is Na and K, respectively. The zirconium tetrachloride was reacted at approximately 1 atm. pressure, and at temperatures of the alkali metal chloride between 425 °C and 525 °C. The densities, melting points, and the corresponding X-ray diffraction patterns for both compounds have been determined.