Abstract: This study explored the feasibility and potential benefit s provided by the addition of through-thicknessstitched composite closed -cell foam sandwich st ructures. For comparison purposes , unstitched foam and Nomexhoneycomb core sandwich panels were produced using the same face sheet s and manufacturing methodology. Thedensity measurements , flexural testing , flatwise tensile and compression , core shear , edgewise compression , anddamage resistance/ damage tolerance test s were performed. The experimental result s show significant increasing inthe flexural stiffness to mass ratio , flexural st rength to mass ratio , out-of-plane tensile and compression st rength ,core shear st rength and modulus , edgewise compression st rength and CAI st rength and failure st rain of the stitchedfoam sandwich st ructures. This innovative concept of stitched foam sandwich st ructures may be utilized in theaircraf t design of lightweight and low-cost st ructures with higher load-carrying capability , lower manufacturing andmaintaining cost .