Abstract Cationic ruthenium sulfine complexes [CpRu(PR´₃)₂(O=S=CHR)]PF₆ have been obtained by a variety of methods. Oxidation of the thioaldehyde complexes [CpRu(PR´₃)₂(S=CHR)]PF₆ with either 2-tosyl-3-phenyl-oxaziridine (PR´₃ = PMe₃ ) or magnesium-monoperoxyphthalate (PR´₃ = 1/2 dppm) gave complexes of arylsulfines (R = Ph, 3-C₆H₄F, 4-C₆H₄Cl, 4- C₆H₄OMe) selectively in their thermodynamically less stable E form. Siloxane elimination from the sulfinato complexes [CpRu(PMe₃)₂(SO₂CHRSiMe₃)] yielded complexes of aliphatic sulfines, [CpRu(PMe₃)₂(O=S=CHR)]PF₆ (R =H,Me). Treatment of [CpRu(dppm)(SO₂CH₂R)] with acetyl chloride led to an oxygen redistribution giving complexes of thioaldehydes [CpRu(dppm)(η²-S=CH₂)]PF₆ and [CpRu(dppm)(η¹-S=CHR)]PF₆ (R = Ph, 4-C₆H₄Cl). The structure of the latter was determined by X-ray crystallography. The loss of oxygen can be suppressed by performing the acylation-elimination sequence in the presence of poly-(4-vinylpyridine). This provided a selective access to complexes of Z-sulfines, [CpRu(PMe₃)₂(O=S=CHR)]PF₆ (R = Ph, 4-C₆H₄Cl) and [CpRu(dppm)(O=S=CHR)]PF₆ (R = Ph, 4-C₆H₄Cl, COOEt, Cl). Complexes of the parent sulfine O=S=CH₂ were also obtained by SO transfer to the methylene complex [CpRu(PMe₃)₂(CH₂)]PF₆ and methylene transfer to the sulfur monoxide complex [Cp*Ru(PMe₃)₂ (SO)]PF₆. Most of the new sulfine complexes exhibit dynamic behaviour in solution, i. e. ligand rotation, ligand inversion, and η² /η¹ hapticity change. O-Alkylation provided the dicationic complex [CpRu(PMe₃)₂ (EtO-S=CHMe)](PF₆)₂, and S-oxidation gave the sulfene complexes [(C₅R₅)Ru(PMe₃)₂ (O₂S=CH₂)]PF₆ (R = H, Me).