Graphene oxide was synthesized by the Hummers method and characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared and ultraviolet-visible spectroscopies’. The obtained material was used as an adsorbent to remove sodium diclofenac from aqueous media. The influence of process parameters (pH, sodium diclofenac concentration, contact duration and adsorbent dose) on graphene oxide efficiency was investigated. A comparative study of the applicability of the Langmuir and Freundlich adsorption models for the description of experimental sodium diclofenac adsorption isotherms was carried out. It was shown that the Freundlich isotherm reflects the adsorption of sodium diclofenac on the graphene oxide from aqueous solutions comparatively better than the Langmuir isotherm.