Hybrid structures composed of multi-layer sheets of polymers and metals offer a great potential for impact protection systems in automotive and aeronautics industries. This work presents an experimental and numerical investigation on the perforation behaviour of layered polymer/metal composites. Penetration tests have been conducted on sandwich panels of aluminium 2024-T3 skins and polyether-ether-ketone (PEEK) cores, using spherical projectiles. The perforation experiment covered impact velocities in the range 250-500m/s. The initial and residual velocities of the projectile were measured, and the ballistic limit velocity was obtained. The impact mechanical behaviour of PEEK core is compared with Ti6Al4V titanium core, for the same areal density of protection. It has been shown high perforation efficiency of PEEK polymer and a promised application for aeronautical protections. A numerical modelling is presented and validated with experimental data.