The adsorptive removal of p-arsanilic acid (ASA) from water using zeolitic imidazolate framework-8 (ZIF-8) materials was investigated for the first time. The adsorption kinetics and adsorbed amount of ASA were improved by introducing mesoporosity into the pristine ZIF-8 structure. The high adsorption capacity of mesoporous ZIF-8 for ASA and facile regeneration of the used adsorbent show that mesoporous ZIF-8 has potential applications in the adsorptive removal of organoarsenic compounds such as ASA. Based on the adsorption results at various pH values and the surface charges on ZIF-8s, the adsorption mechanism of ASA on ZIF-8s can be explained by electrostatic interactions between the positively charged ZIF-8 surface and the anionic forms of ASA. (C) 2015 Elsevier B.V. All rights reserved.