We present a theoretical study of the intermolecular potentials for the Ar, Kr, and Xe-CH4., -CF4 systems. The potential-energy surfaces of these systems have been calculated utilizing second-order Moller-Plesset perturbation theory and coupled-cluster theory in combination with correlation-consistent basis sets (aug-ccpvnz; n = d, t, q). The calculations show that the stabilizing interactions between the rare gases and the molecules are slightly larger for CF4 than for CH4. Moreover, the rare-gas-CX4 ( X = H, F) potentials are more attractive for Xe than for Kr and Ar. Our highest quality ab initio data (focal-point-CCSD(T) extrapolated to the complete basis set limit) have been used to develop pairwise analytical potentials for rare-gas-hydrocarbon (-fluorocarbon) systems. These potentials can be applied in classical-trajectory studies of rare gases interacting with hydrocarbon surfaces.