Treatment of [RuCl2(η6-C6H6)]2 with 1,2-bis(diphenylphosphino)benzene (abbreviation DPB) led to [RuCl(η6-C6H6)(dpb)]Cl (2). When complex 2 in methanol was heated at 50 °C for 13 h, a cationic trinuclear complex [Ru3(μ2-Cl)3(μ3-Cl)2(dpb)3]Cl (3a) was obtained in 75% yield with liberation of the benzene ligand. The cationic trinuclear structure was confirmed by X-ray analysis of [Ru3Cl5(dpb)3]PF6 (3b). Three ruthenium atoms were linked by three μ2-bridging chloride atoms and two face-capped μ3-chloride atoms to form a triangular core of Ru3(μ2-Cl)3(μ3-Cl)2.