The title complex was obtained by the reaction of (mu-SCH2CH2CH2S-)Fe-2(CO)(6) with tris(p-tolyl)phosphine in the presence of the decarbonylating agent Me3NO center dot 2H(2)O in CH2Cl2/MeCN solutions. The molecular structure was determined by X-ray diffraction analysis. The title complex contains a butterfly diiron dithiolate cluster with five terminal carbonyls and a tris(p-tolyl)phosphine. The phosphorus atom of tris(p-tolyl)phosphine occupies an apical position of the square-pyramidal coordination sphere of the Fe2 atom. The van der Waals' interactions stabilize the solid state in the crystal packing.