Two Group 6–Group 10 sulfido mixed-metal complexes, [NEt₄][PdWS₄(S₂CNC₄H₈)] 1 and [NEt₄]₂[PdW₂S₈] 2, have been synthesized via reactions of [Pd(S₂CNC₄H₈)₂] with [NH₄]₂[WS₄] and NEt₄Cl in different molar ratios in dichloromethane. X-Ray crystallographic structure determinations revealed that palladium in 1 is co-ordinated by a pyrrolidinecarbodithioate and a tetrathiotungstate, while in 2 it is co-ordinated by two tetrathiotungstates symmetrically. Both dithiocarbamate and tetrathiotungstate act as bidentate ligands through two sulfur atoms chelating palladium. The Pd–W distances are 2.8669(7) and 2.9008(5) Å in 1 and 2, respectively. Non-linear optical properties of the compounds were studied with a 7 ns pulsed laser at 532 nm. Compound 1 exhibits mainly optical self-defocusing (n₂ = –6.8 × 10^–18 m² W^–1 as measured with a 1.0 × 10^–3 mol dm^–3 acetonitrile solution) with negligible non-linear absorption. Compound 2 exhibits both optical self-defocusing (n₂ = –7.5 × 10^–18 m² W^–1, as measured with a 1.6 × 10^–3 mol dm^–3 acetonitrile solution) and optical non-linear absorption (α₂ = 3.5 × 10^–11 m W^–1).