A methodology for the optimal design of structural mechanical components with sizing, configurational and topological consideration is presented. The optimization involves the minimization of structural weight subject to stress and deflection constraints. A finite element code with internally generated design sensitivities and general element connectivities is implemented in order to solve for the stresses and deflections in the structure. Beam elements with various crossectional configurations are considered. The generalized reduced gradient method is applied to solve the constrained nonlinear programming problem. A hierarchical design optimization approach is taken with topological issues considered at the upper level and geometric and crossectional issues considered at the lower level. An example involving the design of an automotive seat frame structure is presented to demonstrate the approach.