Adsorption of Cu2+ and Zn2+ ions onto clay-poly(N-isopropylacrylamide) nanocomposite with a high clay content was investigated by visible adsorption spectroscopy and atomic absorption spectroscopy. Equilibration time was several hours or more for centimeter-sized specimens but was much shorter for samples with a smaller grain size. Adsorption isotherms of Cu2+ could be reproduced well using the Langmuir equation, and the estimated maximum adsorption amount coincided with the cation-exchange capacity of fluorohectorite-type clay contained in the nanocomposite. Results indicated that the effectiveness of using clay as an adsorbent can be improved by nanohybridization with a hydrophilic polymer.