An efficient and practical synthetic protocol to synthesize nonsymmetrical aryl thioethers by nucleophilic aromatic substitution (SNAr) reaction of nitroarenes by thiols with potassium phosphate as the catalyst is described. Various moderate to strong electron-withdrawing functional groups are tolerated by the system to provide thioethers in a good to excellent yields. We also showed that the present method allows access to 3 drug examples in a short reaction time. Finally, mechanistic studies suggest that the reaction may form the classic Meisenheimer complex through a two-step addition-elimination mechanism.