'On/off'-switchable catalysis by a smart enzyme-like imprinted polymer is reported. This unique imprinted polymer was composed of poly(N-isopropylacrylamide)-containing p-nitrophenyl phosphate-imprinted networks that exhibited temperature-dependent hydrophilicity/hydrophobicity. At a relatively low temperature (such as 20 degrees C), this polymer was capable of vigorous catalysis for the hydrolysis of p-nitrophenyl acetate due to its hydrophilic networks, which enabled access to the imprinted framework. On the contrary, at higher temperatures (such as 40 degrees C), this polymer demonstrated poor catalysis resulting from its dramatically increased hydrophobicity, which inhibited access to the imprinted sites. Unlike previously reported imprinted polymers which lack adjustable networks, this novel imprinted polymer employed thermosensitive poly(N-isopropylacrylamide) networks, thus enabling the switchable catalysis. Crown Copyright (C) 2010 Published by Elsevier Inc. All rights reserved.