The magnetic properties of Ising thin films are studied using a reaction field approximation. The thickness-dependent film Curie temperature T-c(f)(d) is calculated for different surface magnetic moments mu(s) as well as for the case when the exchange parameter I-s that couples surface spins and the exchange interaction Is between spins in the surface and in the first (next) layer, differ from the exchange parameter I-b in the bulk. The layer magnetizations vs. temperature mi(T) are calculated as a function of I-s and I-i. It is found that the curvature of m(i)(T) depends essentially on I-s and I-i. The calculations are carried out assuming nearest-neighbour exchange interactions in the face centred d cubic lattice With the(III) surfaces.