Abstract The isothermal section of the phase diagram of the Dy–Fe–Ge ternary system at 773 K has been investigated mainly by X-ray powder diffraction (XRD), with the aid of differential thermal analysis (DTA) and optical microscopy (OM). Sixteen binary compounds have been confirmed. Five ternary compounds DyFe 4 Ge 2 , DyFe 2 Ge 2 , DyFe 6 Ge 6 , Dy 117 Fe 52 Ge 112 , and Dy 5 Fe 2 Ge 10 have been confirmed in this system at 773 K.