Light weight structures give significant advantages to products in the Industrial sector. Component weight-saving plays a major role in improving the efficiency and performance of assembled systems.The introduction of lighter materials into products using dissimilar material joining techniques can create more weight savings and leads to lighter structures. Structural optimization is another method to optimize the material layout without affecting overall performance of the product.This paper discusses the methods to create lighter structures by the introduction of lighter materials in structures and structural optimization methods. Lighter materials are introduced in the structure using dissimilar material joining techniques. Joining processes such as thermal shrink-fit and mechanical press-fit are useful for metal to metal components. Similarly, adhesively bonded joints are useful for both metal and non-metal (plastics and composites) components.The aim of this study is to combine the advantages of introducing lighter material in structures and optimized design using structural optimization. In this paper detailed study on the structural analysis approach for some of the common dissimilar material joining techniques is presented. Topology optimization methodology is discussed in detail using a case study on a lighter body which is introduced through joining techniques.A parametric optimization method is proposed in this paper to consider the optimal percentage of weight saving and the overall cost of the structure which includes the material and manufacturing cost. This paper presents a novel approach of introducing lighter materials in combination with structural optimization.