A method was established for enrichment of trace levels of Co(II), Ni(II), Fe(II), and Cu(II) ions in aqueous solutions. These metals were quantitatively retained on an Amberlite XAD-4 column, after complexation with di-2-pyridyl ketone thiosemicarbazone (DPKT). After elution with 1 M HNO(3) in acetone, concentration of metals were measured by atomic absorption spectrometry. The effect of major cations of drinking and tap water samples on the sorption of metal ions also were investigated. The amount of the analyte metal ions determined after preconcentration was basically in agreement with the added amount.