The asymmetric unit of the title compound, [RuCl2(C6H6)(C18H27P)]·1.5C6H6, contains one mol-ecule of the Ru(II) complex and one and a half solvent molecules as one of these is located about a centre of inversion. The Ru(II) atom has a classical three-legged piano-stool environment being coordinated by an η(6)-benzene ligand [Ru-centroid = 1.6964 (6) Å], two chloride ligands with an average Ru-Cl bond length of 2.4138 (3) Å and a dicyclo-hexyl-phenyl-phosphane ligand [Ru-P = 2.3786 (3) Å]. The effective cone angle for the phosphane was calculated to be 158°. In the crystal, weak C-H⋯Cl hydrogen bonds link the Ru(II) complexes into centrosymmetric dimers. The crystal packing exhibits intra- and inter-molecular C-H⋯π inter-actions resulting in a zigzag pattern in the  direction.