The reaction of the complex [{(η6-C6Me6)Ru(μ-Cl)Cl}2] 1 with sodium azide ligand gave two new dimers of the composition [{(η6-C6Me6)Ru(μ-N3)(N3)}2] 2 and [{(η6-C6Me6)Ru(μ-N3)Cl}2] 3, depending upon the reaction conditions. Complex 3 with excess of sodium azide in ethanol yielded complex 2. These complexes undergo substitution reactions with monodentate ligands to yield monomeric complexes of the type [(η6-C6Me6)Ru(X)(N3)(L)] {X=N3, Cl, L=PPh3 (4a, 9a); PMe2Ph (4b, 9b); AsPh3 (4c, 9c); X=N3, L=pyrazole (Hpz) (5a); 3-methylpyrazole (3-Hmpz) (5b) and 3,5-dimethyl-pyrazole (3,5-Hdmpz) (5c)}. Complexes 2 and 3 also react with bidentate ligands to give bridging complexes of the type [{(η6-C6Me6)Ru(N3)(X)]2(μ-L)} {X=N3, Cl, L=1,2-bis(diphenylphosphino)methane (dppm) (6, 10); 1,2-bis(diphenylphosphino)ethane (dppe) (7, 11); 1,2-bis(diphenylphosphino)propane (dppp) (8, 12); X=Cl, L=4,4-bipyridine (4,4′-bipy) (13)}. These complexes were characterized by FT-IR and FT-NMR spectroscopy as well as by analytical data.The molecular structures of the representative complexes [{(η6-C6Me6)Ru(μ-N3)(N3)}2] 2, [{(η6-C6Me6)Ru(μ-N3)Cl}2] 3,[(η6-C6Me6)Ru(N3)2(PPh3)] 4a and [{(η6-C6Me6)Ru(N3)2}2 (μ-dppm)] 6 were established by single crystal X-ray diffraction studies.