Experimental results for indium adsorption onto some ion exchange resins of different organic functional groups are presented. The following resins were tested: Ionac(R) SR-5 and Ionac(R) SR-12 (Sybron Chemicals), S950 (Purolite Company) and Amberlite(R) IR-120P (Rohm&Haas, Brazil). The indium concentration in the aqueous solution was based on a typical indium. sulfate leach liquor obtained from a zinc hydrometallurgical processing route of a Brazilian plant and treated with solvent extraction for some impurities removal. The performance of the resin was based on the indium adsorption loading capacity and its selectivity concerning iron as a typical impurity present in the solution. Some parameters, such as initial pH and volume of the aqueous feed solution and contact time were studied. Batch tests were carried out. The experimental results allowed to select the chelating resin containing iminodiacetic acid groups with high potential for purification of the indium sulfate solution. (C) 2003 Elsevier Science Ltd. All rights reserved.