The tetrameric compound [Ta2Cl4 (μ-Cl)2(μ-SC4H8)]2(μ-Ph2PCH2CH2PPh2)2.2C7H8 has been prepared from the reaction of Ta2Cl4(SC4H8)2 (μ-Cl)2 (μ-SC4H8) (1) with Ph2PCH2CH2PPh2(dppe). The compound crystallizes in the space group Bbcm, which is the bca setting of space group No. 64, Cmca. The cell parameters are a = 12.706 (6) A, b = 27.240 (7) A, c = 25.93 (2) A, V = 8976 (9) A3, and Z= 4. The structure consists of two confacial bioctahedral units of Ta2Cl4(μ-Cl)2(μ-SC4H8) bridged by two Ph2PCH2CH2PPh2 ligands. The Ta=Ta double-bond distance within the bioctahedral units is 2.704 (2) A with no metal-metal bonding between the separate dimeric units of the tetramer. To our knowledge this compound is the first tetrameric tantalum(III) compound reported in the literature. It is a deviation from the products previously reported for the reactions of analogous niobium or tantalum dimeric compounds with bidentate phosphine ligands, all of which result in the formation of edge-shared dimeric compounds of the type M2C16(PP)2(where PP = bidentate phosphine ligand). The fact that the bridging (SC4H8) ligand is not substituted in the tantalum tetramer suggests that the ligand is less labile in 1 than in its niobium analogue.