A number of ruthenium(II) complexes containing an NNS chelating thioether ligand (L) have been synthesized and characterized by elemental analysis, UV-visible, IR and 1 H NMR spectroscopy and cyclic voltammetry. Ru(L)(PPh 3 )Cl 2 (1) has been characterized by X-ray diffraction. Structural features of (1) indicate a distorted octahedral coordination environment around the ruthenium(II) centre. The two chlorides are cis to each other with the Ru--Cl(1) bond trans to PPh 3 longer than the Ru--Cl(2) bond. Several mixed-ligand complexes containing bipyridine, phenanthroline, 2-picolinate and oxalate were also isolated and the structure of one of the heterochelates has been solved. [Ru(L)(PPh 3 )(bpy)](ClO 4 ) 2 (2) has also been structurally characterized. The structure and properties of (2) correspond to the predictions based on the structure of (1).