Organoarsenic　compounds　are　emerging　contaminants　because　of　their　considerable　solubilities　in　water　and　the　highly　toxic　inorganic　arsenic　species　formed　during　their　biotic　and　abiotic　degradation　in　the　natural　environment.　Herein,　the　adsorption　of　p-arsanilic　acid　(p-ASA),　a　typical　organoarsenic　compound,　was　studied　by　employing　an　amino-functionalized　indium-based　metal–organic　framework　(NH2-MIL-68(In))　and　pristine　MIL-68(In).　Adsorption　batch　experiments　reveal　that　NH2-MIL-68(In)　has　a　higher　adsorption　capacity　(401.6　mg　g−1),　affinity　(0.0552　L　mg−1),　and　adsorption　rate　(5.79　×　10−4　g　mg−1　min−1)　toward　p-ASA　than　those　of　pristine　MIL-68(In).　Moreover,　the　adsorption　of　p-ASA　was　spontaneous　and　exothermic,　and　obeyed　a　pseudo-second-order　model　with　intraparticle　diffusion.　The　adsorption　mechanism　is　proposed　to　involve　synergism　between　π-π　stacking　and　hydrogen-bonding　interactions.　The　NH2　moiety　introduced　into　the　MIL-68(In)　greatly　improves　its　adsorption　performance　by　enhancing　hydrogen　bonding.　This　study　provides　an　important　theoretical　and　experimental　basis　for　the　application　of　MOFs　to　the　removal　of　organoarsenic　compounds　such　as　p-ASA.　©　2018　Elsevier　B.V.