Natural　zeolites　are　abundant　and　low　cost　resources,　which　are　crystalline　hydrated　aluminosilicates　with　a　framework　structure　containing　pores　occupied　by　water,　alkali　and　alkaline　earth　cations.　Due　to　their　high　cation-exchange　ability　as　well　as　to　the　molecular　sieve　properties,　natural　zeolites　have　been　widely　used　as　adsorbents　in　separation　and　purification　processes　in　the　past　decades.　In　this　paper,　we　review　the　recent　development　of　natural　zeolites　as　adsorbents　in　water　and　wastewater　treatment.　The　properties　and　modification　of　natural　zeolite　are　discussed.　Various　natural　zeolites　around　the　world　have　shown　varying　ion-exchange　capacity　for　cations　such　as　ammonium　and　heavy　metal　ions.　Some　zeolites　also　show　adsorption　of　anions　and　organics　from　aqueous　solution.　Modification　of　natural　zeolites　can　be　done　in　several　methods　such　as　acid　treatment,　ion　exchange,　and　surfactant　functionalisation,　making　the　modified　zeolites　achieving　higher　adsorption　capacity　for　organics　and　anions.　(C)　2009　Elsevier　B.　V.　All　rights　reserved.