The structure and magnetic properties of Nd1-xHoxMn2Ge2 (0.0 <= x <= 1.0) germanides were studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) techniques and AC magnetic susceptibility measurements. All compounds crystallize in the ThCr2Si2-type structure with the space group 14/mmm. Substitution of Ho for Nd leads to a linear decrease in the lattice constants and the unit cell volume, and the magnetic interactions in the Mn sublattice cross over from a ferromagnetic character to an anti ferromagnetic one. A typical SmMn2Ge2-like behavior is observed for x = 0.6 and 0.8. The results are collected in a phase diagram. (c) 2006 Elsevier Ltd. All rights reserved.