The adsorption of cassava starch on quartz, kaolinite and goethite is presented as a function of starch concentration and pH. Cassava starch adsorbs on these three minerals in the order: kaolinite > goethite > quartz. Zeta potential measurements have been made for these minerals in the absence and presence of cassava starch. These measurements indicate that cassava starch adsorbs by hydrogen bonding to the surface of each mineral.