The influence of foam infill on the blast resistivity of corrugated steel core sandwich panels was investigated experimentally using a shock tube facility and high speed photography and numerically through Finite Element Methods (FEM). After verifying the finite element model, numerical studies were conducted to investigate the effect of face sheet thickness (1, 3 and 5 mm), corrugated sheet thickness (0.2 mm, 0.6 mm and 1 mm), and boundary conditions (Simple Supported and Encastre Supported on the back sides) on blast performance. Experimental and FEM results were found to be in good agreement with R-2 values greater than 0.95. The greatest impact on blast performance came from the addition of foam infill, which reduced both the back-face deflections and front-face deflections by more than 50% at 3 ms after blast loading at a weight expense of only 2.3%. However, increasing face sheet thickness and corrugated sheet thickness decreased the benefit obtained from foam filling in the sandwich structure. Foam infill benefits were more prominent for Simple Supported edge case than Encastre Supported edge case. (C) 2013 Elsevier Ltd. All rights reserved.