Trans-dichloro-2,3-naphthalenediamine bis[(2-methoxyethyl)¬(diphenyl)¬phos¬phine]¬¬ruthenium(II) complex Cl2Ru(h1-Ph2PCH2CH2OCH3)2(C10H10N2) has been obtained by reaction of equimolar amounts of Cl2Ru(PÇO)2 complex 2 with one equivalent of 2,3-naphthalenediamine as co-ligand in very good yield. The structure of this new complex 3 was confirmed by elemental analysis, IR, 31P-NMR 1H-NMR, 13C-NMR, UV-visible spectroscopy and FAB-MS.