Insertion of CS₂ into the Ru−H bond of cis-[(dppe)₂Ru(H)₂] takes place to afford the hydride dithioformate complex trans-[(dppe)₂Ru(H)(SC(S)H)]. The hydride dithioformate complex reacts under very mild conditions with MeX (X = OTf, I) to give the hydride methyldithioformate derivative trans-[(dppe)₂Ru(H)(SC(SMe)H)][X]. Three different pathways have been found to cleave off the ester moiety from the metal complex. A method to recover the ruthenium starting material upon elimination of the methyldithioformate is presented. This is a novel case of C₁ chemistry using carbon disulfide.