The projectile impact and energy absorption characteristics of the corrugated aluminum cored E-glass/polyester composite sandwich structures were determined at the impact velocities of 150 m/s. For comparison, E-glass/polyester sandwich structures cored with aluminum foam were also investigated. The test conditions were kept the same for each structure in order to identify the impact properties at the similar test conditions. The composite and the foam core composite sandwiches were produced by vacuum assisted resin transfer molding and the mechanical tests were performed on the composite and core samples based on ASTM. High strain rate tests were performed using a compression type Split Hopkinson Pressure Bar and drop weight test set-up. It was found that aluminum foam sandwich structures had higher ballistic limit and energy dissipating performance than corrugated aluminum sandwich structures; however, as the thickness of the face sheets increased the corrugated aluminum cores were observed to be more effective. The results showed that corrugated aluminum structures had the potentials to be used as core material in composite sandwich structures.