Recent experimental results on the temperature dependence of the hyperfine field acting on dysprosium impurity nuclei in gadolinium metal are used to check the validity of the molecular field model for such systems, and to reduce the Dy&sngbnd;Gd exchange coupling parameter. It is concluded that the molecular field model is able to explain successfully the experimental observations. The exchange field acting on dysprosium ions embedded in gadolinium metal, &bgr;He(0°K) /k=110±5°K, is approximately equal to the field acting on the gadolinium ions (&bgr;He(0°K) / k=98°K).