In this paper, three decision making methods-Smarts, Promethee, and a fuzzy decision algorithm-were utilized to choose the final optimal solution of multiobjective problems. An inverse electromagnetic scattering problem, as well as some analytical problems, was considered in this study. The a posteriori decision was performed by applying each method to the nondominated front previously met by an evolutionary algorithm. The results confirm their usage when considering convex problems, but also show that both Smarts and Promethee can not always be applied to nonconvex problems