Solid state metathesis reactions between RECl3 (RE = La, Ce) and Li2CN2 at 800 degreesC have led to the discovery of the rare earth chloride carbodiimide nitrides La2Cl(CN2)N (1) and Ce2Cl(CN2)N (2), respectively. Single crystal X-ray diffraction analyses revealed that 1 and 2 crystallize isotypic in an orthorhombic system (Cmmm, Z = 4, a = 13.3914(8) Angstrom, b = 9.6345(7) Angstrom, c = 3.9568(2) Angstrom for 1 and a = 13.340(1) Angstrom, b = 9.5267(8) Angstrom, c = 3.9402(5) A for 2). The crystal structures of 1 and 2 contain linear chains of edge-sharing octahedra built from rare earth metal atoms. Similar to [[M6X8] type clusters, the [RE6] octahedra are capped by eight nitrogen atoms above their faces, of which four are from N3- ions and the other four are from (CN2)(2-) ions. The chains are interconnected by bridging (CN2)(2-) to form a three-dimensional ' network with Cl- ions in linear channels. Compounds 1 and 2 are surprisingly stable toward air and water. They have been characterized by thermal analysis, infrared spectroscopy, and magnetic susceptibility studies.