The effect of the competing nature of exchange interactions on the magnetic properties (e.g. transition temperature Tc, susceptibility and magnetization) of disordered Ising alloys ApB1-p where both A and B represent magnetic atoms are investigated. The free energy is obtained using a cluster-variational method, where the interactions within the clusters of all possible configurations are treated exactly and the rest of the interaction is replaced by an effective variational field. The frustration effect is introduced taking either one or both the exchange integrals JAB and JBB to be antiferromagnetic whereas JAA is ferromagnetic. The phase boundary shows re-entrant behaviour within a range of concentration p, and Tc depends sensitively on the strength of the antiferromagnetic bond. The low temperature phase has larger field response and higher non-linear susceptibility compared to the high temperature paramagnetic phase. The plot of inverse of paramagnetic susceptibility vs. T shows a strong curvature which increases with disorder. The effective exponent γ*(T) of the susceptibility passes through a maximum as T is increased from Tc. The qualitative aspects of these results are similar to the observed behaviour of many amorphous alloys. © 1985.