Abstract: The wastewaters letting out from small-scale industries, like electroplating, smelting, battery manufacture, tanneries etc. are contaminating the nearby water source by increasing the heavy metal concentrations mainly Cadmium and Zinc etc. These cause acute poisoning in humans high blood pressure, kidney damage and destruction of testicular tissue, red blood cells, stomach cramps, skin irritations, vomiting and respiratory disorders. Therefore, these wastewaters are to be treated using cost effective methods. In recent years, the adsorption of metal ions using low cost adsorbents is very promising method. This study presents adsorption investigations in removal of Cadmium and Zinc using low cost adsorbents of Fly Ash and Cenospheres (derived from power plant fly ash) from aqueous solution and the results were compared with Activated Carbon. Batch adsorption experiments were conducted in order to evaluate the removal efficiency of these adsorbents and the parameters effect like temperature, contact time, pH, adsorbent dosage and initial concentration were studied. The kinetics studies were made to estimate adsorption rate constants. The thermodynamic parameters were estimated for these adsorbents. The adsorption isotherms of Langmuir, Freundlich and Temkin constants for all the adsorbents were determined and the Langmuir adsorption isotherms recommended.