The adsorption of mercury on zirconium oxide from aqueous solution has been studied in relation to concentration of adsorbent and adsorbate. The influence of contact time, buffer composition, pH, and foreign ions was also investigated. Thiosulfate, iodide, thiocyanate, EDTA, cyanide and Li(I) drastically reduced adsorption. Adsorption of other metal ions under the same conditions was also investigated. Based on these data, separation of mercury from antimony and neodymium can be achieved.