The uptake of mercury, silver and cadmium ions from aqueous solutions by the sodium form of heulandite (NaHeu) has been studied at room temperature using radiochemical techniques. The concentration of the used solutions was varied approximately from 500 to 20000 mg/l. The concentration of the metal ions in the solutions after the treatments, determined by tracer techniques, was used for the determination of the uptake extend. At lower concentrations the uptake sequence of the investigated metal ions by the NaHeu is Ag > Hg > Cd, while at higher concentrations the sequence is Hg > Ag > Cd. The uptake is attributed not only to ion-exchange procedures but also to adsorption of some ionic species onto the surface of NaHeu grains.