Abstract Investigations made by powder X-ray diffraction, susceptibility measurements and neutron diffraction experiments on new ternary germanides RCoGe (RLaNd) are reported. They crystallize in the well-known tetragonal CeFeSi-type structure (space group P4/nmm). This is closely related to the ThCr 2Si 2- and CrB-type structures and can be described as isolated “ThCr 2Si 2 blocks” (BaAl 4 slab) connected via R-R contacts (CrB slab). LaCoGe is a Pauli paramagnet, whereas CeCoGe and PrCoGe are Curie-Weiss paramagnets down to 1.6 K. NdCoGe orders antiferromagnetically below T N = 8 K ; its magnetic structure consists of ferromagnetic (001) Nd layers (with moments lying in the (001) plane) antiferromagnetically coupled along the c axis with the sequence + + − − ( μ Nd = 2.62(4) μ B). In all compounds, no local moment was detected on the cobalt site. The results are discussed and compared with those obtained on the closely related NdCo 2Ge 2, NdGe and isotypic RFeSi compounds.