The intermetallics Tb x Dy 1 - x Fe 2 (x = 0.0, 0.2, 0.27, 0.3, 0.5, 0.7 and 1.0) with the cubic Fd3m, MgCu 2 type of structure were studied by the e 5 7 Fe Mossbauer effect. Measurements were performed at 78 and 300 K. The hyperfine interaction parameters, i.e. the isomer shift, the magnetic hyperfine field and the parameter of quadrupole interaction, are presented vs. x. At 78 K for x<0.4 only one set of hyperfine interaction parameters appears, whereas for x> 0.4 two different sets of parameters are observed. To some extent analogous dependences at 300 K appear. The transition from the [100] direction of the easy axis of magnetization to the [111] direction is deduced from the analysis of Mossbauer spectra. The possible nature of the transition is discussed.