The computational drawbacks of existing numerical methods have forced researchers to rely on heuristic algorithms. Heuristic methods are powerful in obtaining the solution of optimization problems. The Particle Swarm Optimization (PSO) method is a numerical optimization technique that simulates the social behavior of birds, fishes and bugs. Similar to birds seek to find food, the optimum design process seeks to find the optimum solution. In the present study, a combination between nominal PSO and Gaussian PSO is applied to get the optimum design for steel structures. A modified fly back technique is used to deal with constraints. Standard design problems selected from literatures are used to evaluate the performance of the proposed technique. The comparison showed that design obtained using the present algorithm is more efficient and economical than that provided by other design approaches.