The effect of some interfering ions on the adsorption of Pb (II) was studied at room temperature. Experimentally, 0.1 g of the Co Mo LDH was suspended in 20 mL of the Pb (II) aqueous solution (∼370 ppm) containing 300 ppm of NaNO3, KNO3, Cu (NO3)2 or Mn (NO3)2 on a separate basis. The solutions were stirred for 120 min then the adsorbent was separated out by centrifugation. The solutions containing the different ions were then subjected to AAS analysis.