The presence of pharmaceuticals, such as non-steroidal anti-inflammatory drugs (NSAIDs) in the aquatic environment represents a worldwide threat. NSAIDs are considered “emerging contaminants” of water since the traditional methods are not designed to efficiently remove them. Aiming to overcome the limits of the conventional wastewater treatment plants, we propose molecularly imprinted polymers (MIPs) as valid tools for selective adsorption and removal of these drugs from water. In particular, in this work, we have prepared diclofenac-selective MIP by a simple bulk polymerization process. After the characterization of the synthetized polymers, the binding abilities were evaluated in detail through the adsorption of diclofenac in aqueous solution and compared with the abilities of a corresponding non-imprinted polymer used as a reference. Thanks to the imprinting effect, the prepared MIP adsorbs with extreme selectivity its template molecule, i.e. the diclofenac. This effect was evaluated by testing the adsorption abilities towards different drugs, such as acetylsalicylic acid and trimethoprim. In addition, MIP reusability was demonstrated after a simple regeneration step. The strength of this work is due to the low cost synthesis of MIP and to its optimal performance of molecular recognition in water, differentially from many of the traditional MIPs, usually used with organic solvent. Such peculiarities make the material potentially applicable for water treatment on a large scale.