The crystal structure of the title complex has been determined by the heavy-atom method from X-ray diffractometer data and refined to R 0.052 for 2 997 independent reflections. Crystals are triclinic, space group P, a= 16.08(1), b= 11.907(5), c= 9.693(3)A, α= 103.04(3), β= 77.80(4), γ= 94.15(4)°, Z= 2.The complex, reported previously as [Ru(dtc)2CO](dtc–= CS2–·NEt2), is dimeric, the sixth co-ordination position in the pseudo-octahedral co-ordination sphere about each ruthenium being trans to the carbonyl (mean Ru–C 1.78 A) and filled by a bridging sulphur atom from one of the ligands about the other ruthenium (mean Ru–S 2.55 A); the remaining Ru–S distances are slightly longer than those usually found (mean 2.399 A). The Ru ⋯ Ru distance [3.654(2)A] indicates there is no metal–metal interaction. The molecule approximates to C2 point-symmetry.