The experimental sorption isotherms of fluoride were compared for several aluminosilicate <br/>clays. A competitive Langmuir isotherm incorporating pH dependence in fluoride sorption was <br/>used to model the experimental results. Bentonite was determined to be a far superior fluoride <br/>sorbent than kaolinite quantitatively, although results suggest that fluoride sorption by bentonite <br/>may not be achieved through the same sorption mechanism as for kaolinite. Factors found to <br/>influence fluoride sorption include solution pH, clay surface area, aluminium content and the <br/>presence of certain exchangeable cations capable of forming fluoride precipitates. Characterisation <br/>of fluoride sorption behaviour by clay mixtures was achieved through weighted averaging of the <br/>sorption behaviour for the individual clays of the mixture.