An experimental study of in-plane compressive behaviour of unsymmetrical composite sandwich panels was conducted. Two skin thickness combinations were 8/6 plies and 16/12 plies. Both cross ply and quasi-isotropic lay-ups were used in each combination. All sandwich panels were impactdamaged and their dominant damage mechanisms were established. All impact-damaged as well as baseline panels were compression tested. The effects of lacking the symmetry, skin thickness and skin lay-up on CAI strength was examined along with the role of the core.