Abstract We have studied the structural evolution and the occurrence of magnetic ordering in the series of the hexagonal pseudoternary DyMn 6− x Cr x Ge 6 compounds by means of neutron diffraction. We have shown that the ideal HfFe 6Ge 6 structure persists up to fairly high Cr concentrations. The substitution of Cr for Mn leads to a linear increase of the c/ a ratio but gives rise to a structural distortion when x>4. This distortion has been explained in terms of partial atomic disordering of the Dy and Ge atoms. The magnetic phase diagram of DyMn 6− x Cr x Ge 6 has been studied by neutron diffraction in the whole concentration range at temperatures between 1.5 K and 300 K. We have confirmed results obtained earlier from magnetic measurements that the antiferromagnetic ordering of the Mn sublattice breaks down in the Cr rich regime and leads to the absence of any long-range magnetic ordering above 1.5 K in the compounds with x=4, 5 and turns to ferrimagnetism for x=6 as a consequence of a structural distortion.