The magnetic properties of the ternary intermetallic RRhGe (R = Dy and Tm) were investigated by magnetic and neutron diffraction measurements. These compounds crystallize in a TiNiSi-type orthorhombic structure and are antiferromagnets with the Neel temperature 20 K (R = Dy) and 6.2 K (R = Tm). The neutron diffraction data reveal that the magnetic order in TmRhGe is collinear with the magnetic unit doubled along the b-axis respective to the crystal one. PACS numbers: 75.30.Gr, 75.30.Kz, 75.50.Ee