Optimization methods are increasingly used to design structures. Structural optimization with linear static analysis is pretty much mature in methodology and therefore several codes now have optimization capability for linear analysis. This is in contrast to optimization with crash and impact responses encountered in automotive, defense, transportation safety and other fields. Impact responses do not present simplicities as with linear static responses. They are highly nonlinear and noisy (i.e. non smooth) preventing the use of conventional optimization methods based on gradients or sensitivities. Also, impact analyses are usually computationally costly. Such difficulties motivated the development of effective and efficient methods for impact optimization. This book elaborates structural optimization procedure under crash and impact loading. For this purpose, analysis and optimization methods are discussed in detail. Impact optimization problems are solved from several areas.