Black, air-stable crystals of the new ruthenate(V) Sr3(Ag2/3Sr1/6)RuO6 were grown in a silver ampoule using KO2 as oxidative flux. X-ray diffraction on single-crystals revealed a rhombohedral structure with the space group R[[EQUATION]]c. Sr3(Ag2/3Sr1/6)RuO6 crystallizes isostructural to Sr4PtO6 in the K4CdCl6 structure type. By sharing trigonal faces, alternating [RuO6] octahedra and [(Ag2/3Sr1/6□1/6)O6] trigonal prisms form segmented chains running parallel to the crystallographic c-axis. Eightfold coordinated strontium cations are located between the rods. Despite the wide spatial separation of the magnetic cations (588 and 594 pm), Sr3(Ag2/3Sr1/6)RuO6 shows antiferromagnetic order below the relatively high Néel temperature of 79 K in magnetic fields up to at least 9 T, as measurements of the magnetic susceptibility and heat capacity show. Despite the pseudo one-dimensional character of the structure, the characteristic of the susceptibility indicates a three-dimensional coupling of magnetic ions.