In the present work, chitosan was modified with the incorporation of nano-Al2O3 and impregnation with Cu2+ to prepare Cu–chitosan/Al2O3 nanocomposite. The modified adsorbent was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) techniques. The adsorption behaviors of neat chitosan, chitosan/Al2O3 nanocomposite and Cu–chitosan/Al2O3 nanocomposite adsorbents for removal of cefixime from water were investigated by adsorption isotherms and kinetic studies at room temperature. The adsorption equilibrium data for all adsorbents were well fitted to Langmuir isotherm model. According to the Langmuir isotherm, the maximum adsorption capacity of 30.5 mg/g was obtained for the modified adsorbent which is much higher than that of neat chitosan. The kinetic data for three types of adsorbents were in good agreement with pseudo-first-order kinetic model. A high selectivity was obtained for adsorption of cefixime by the modified adsorbent in the presence of natural waters common anions as interfering agents. The modified adsorbent exhibited good regeneration ability during several adsorption-desorption cycles.