In this study, the Modified Adolescent Identity Search Algorithm (MAISA) is proposed to optimize the weight of skeletal structures. The MAISA is a population-based method, similar to other metaheuristic methods. The most advantages of the proposed algorithm are its simplicity and having only one setting parameter. This research aims to increase the balance between exploration and exploitation, improve the convergence rate, and reduce the possibility of being trapped in local points. The applied changes extend the global search at the beginning of the optimization process, and as the number of iterations increases, the possibility of local search increases non-linearly. To evaluate the performance of the proposed method, several benchmark skeletal structure problems have been designed and optimized using the LRFD method under the requirements of the AISC design regulations. The objective function is to calculate the minimum weight of a structure by selecting appropriate discrete sections and considering the deformation and stress constraints. To demonstrate the superiority of the MAISA algorithm, its results have been compared with some popular metaheuristic algorithms. The results show that the proposed algorithm performs better than other metaheuristic methods.