  We present calculations of the leading and $O(1/N_f)$ terms in a large-$N_f$
expansion of the $\beta$-functions and anomalous dimensions for various
supersymmetric gauge theories, including supersymmetric QCD. In the case of
supersymmetric QCD, we show that our $O(1/N_f)$ approximation displays an
infra-red fixed point in the conformal window $3N_c/2 < N_f < 3N_c$.
