A new design and optimization of the structure of a self-portable frigorific trailer is presented. Self-portable trailers are different from usual portable trailer structures in that it is the structure itself which supports all load requirements. The weight optimization of the frigorific self-portable trailer can be achieved due to the great number of possible combinations which are feasible with different kinds of materials and their corresponding geometric configurations. This involves a redesign of the initial structure as well as the ultimate calculation, obtaining a 30% weight saving.