A new heteropolyacid-based cation exchanger zirconium(IV) selenomolybdate has been synthesized, characterized using I.R., X-ray, TGA, DTA techniques. Its composition was found to be Zr:Se:Mo::2.5:0.7:1.6 and it is quite chemically stable. It exhibits 0.94 meq/g ion-exchange capacity for Na+ ions. Its distribution behavior for 16 metal ions has been studied and its utility has been employed by achieving separations Zn2+-Cd2+, Zn2+-Co2+, Ni2+-Cd2+ and Ni2+-Co2+ on its column. (C) 2000 Elsevier Science B.V. All rights reserved.