The K2CO3-mediated benzylation of β-ketosulfoxides 4 with 2.0 equiv of benzylic halides 5 affords benzylic arylsulfoxides 6 in moderate yields along with trace amounts of chalcones 7. The products 6 are assumed to form in situ intermediates of sulfenate anions from β-ketosulfoxides which are commonly involved in carbon–sulfur bond formation. A plausible mechanism has been proposed.