Abstract: Using a simple and convenient method, we have prepared the mononitrosyl compound Mo(NO)(a-C₁₀H₇CS₂)₃·1/2C₄H₈O₂. The crystal structure of this compound has been determined by the singlecrystal X-ray diffraction method.The crystal belongs to monoclinic space group C_2h⁵ - P2₁/a with unit cell parameters a = 14.198(6)Å. b= 12.844(5) Å, c = 18.205(8) Å, β = 101.34(3)°, V = 3254.9ų and Z=4. The structure was refined to R = 0.0947 for 3356 reflections.The coordination number for the Mo atom is seven. The coordination polyhedron around the Mo atom is semewhat distorted pentagonal bipyramid. The linear group of Mo—N—O occupies an axial position. Three a-dithionaphthoate ligands coordinate to Mo atom through the Satoms.