Chromatographic extraction of cobalt and uranium from nitrate solution on Al-13-phosphatoantimonic acid and Dowex 50X8 resin at 0.6 ionic strength and pH 2 was studied. Saturation capacity was studied and found to be 0.8 and 0.5 meq/g for Co2+ and 1.1 and 0.8 meq/g for UO22+ ions, using Al-13-phosphatoantimonic acid (Al-13-PAA) and Dowex 50X8, respectively. The effect of flow rate and on the column performance was investigated. Theoretical plate height and Van Deemter equation parameters were also evaluated.