Sorption of hexavalent chromium ions from aqueous solution by poly 4-vinyl pyridine [Poly(4-VP)] was studied. The batch method was applied for adsorption processes. The effects of initial ion concentration, time, pH and temperature on adsorption were investigated. A treatment time of 60 min was found to be sufficient to reach equilibrium. pH 3.0 was found as the optimum pH value for the process. The maximum adsorption performance was achieved at 86.7 mg g-' using 500 mg L-1 Cr (VI) solutions. The process of adsorption of Cr (VI) was explained by Langmuir isotherm. (c) 2006 Wiley Periodicals, Inc.