Coal-burning plants produce large amounts of fly ash as a residue. Fly ash has been used in construction, agriculture, metal recovery and water pollution control. This paper considers the efficiency of fly ash in the removal of heavy metals (Cd and Cu). The fly ash is shown to be an effective metal adsorbent for these two metals. Adsorption capacity increases as metal initial concentration decreases. The removal phenomenon appears to be that the fly ash neutralises the metal solution due to its alkaline nature. The presence of high ionic strength, or appreciable quantities of Ca and Cl ions does not have a significant effect on the adsorption of these metals by fly ash.