The compounds A(3)A’RuO6 (A = Ca, Sr; A’ = Li, Na) have been synthesized by solid state reactions and studied by X-ray powder diffraction and magnetometry. They all adopt the K4CdCl6 (Sr4PtO6) structure with the cations A’ and Ru occupying the trigonal prismatic and octahedral sites respectively. Infinite chains of octahedra and trigonal prisms sharing faces run parallel to the c axis, the chains being separated by the cations A (Ca, Sr). The validity of this description of the structure is discussed in the light of magnetic susceptibility data which suggest that these phases all transform to a magnetically ordered state in the temperature range 70 < T/K < 120. Preliminary results of powder neutron diffraction experiments confirm the presence of long-range magnetic order in the low temperature phase.