Treatment of [RuCl2(p-cymene)]2 with sodium 2,6-dimethylbenzenethiolate or sodium 2,4,6-triisopropylbenzenethiolate in methanol afforded a mononuclear five-coordinated ruthenium thiolate complex, Ru(SAr)2(p-cymene) (2a: Ar = 2,6-dimethylphenyl; 2b: 2,4,6-triisopropylphenyl), whose structure is determined by X-ray analysis of 2a.