A new, easy, sensitive, and environmentally friendly separation and preconcentration method was developed to determine Cu(II), Fe(III), Pb(II), and Ni(II) at trace levels by use of a column filled with sea sponge without any complexing reagent, and atomic absorption spectrometry. The influences of analytical parameters, such as pH of the solutions, type of eluent, volume of sample, solution and eluent flow rates, and diverse ions, were examined for the quantitative recoveries of the analyte ions. The metal ions were eluted from the column by using 2 M HNO3. Accurate results were found for spiked samples after applying the preconcentration method. The LOD values were found to be between 1.5 and 5.6 mu g/L based on three times the SD of the blanks. The method has been successfully applied to determine Cu(II), Fe(III), Pb(II), and Ni(II) ions in tap water samples, mineral water samples, and a certified reference material.