In the title triangulo-triruthenium compound, [Ru(3)(C(36)H(27)As)(C(25)H(22)P(2))(CO)(9)], the bis-(diphenyl-phosphan-yl)methane ligand bridges an Ru-Ru bond and the monodentate arsine ligand bonds to the third Ru atom. Both the arsine and phosphine ligands are equatorial with respect to the Ru(3) triangle. In addition, each Ru atom carries one equatorial and two axial terminal carbonyl ligands. In each biphenyl unit, the phenyl rings are twisted from each other, making dihedral angles of 51.22 (18), 42.94 (16) and 26.95 (16)°. The arsine-substituted phenyl rings make dihedral angles of 61.22 (15), 87.17 (15) and 83.32 (15)° with each other. The dihedral angles between the two benzene rings are 85.52 (18) and 81.77 (15)° for the two diphenyl-phosphanyl groups, respectively. In the crystal, mol-ecules are linked into dimers by inter-molecular C-H⋯O hydrogen bonds. Weak inter-molecular C-H⋯π and π-π [centroid-centroid distance = 3.6981 (18) Å] inter-actions stabilize the crystal structure.