The release of drugs and their metabolites into the environment is of a great concern, as far as the water pollution is concerned. One can cite oxytetracycline which is used in large quantities and it is essential to reduce its presence in aquatic environments. The present study concerns the adsorption process of oxytetracycline onto peanut shells coated with polyaniline as well as the influence of different physico-chemical parameters such as contact time, concentration, solution pH, ionic strength, and temperature on the retention capacity. The effect of coating on the performance of the adsorption was clearly put into evidence and a thermodynamic study showed that the reaction was exothermic. The results confirmed the effectiveness of the adsorption process for the decontamination of aquatic environments loaded with oxytetracycline. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.