In this study, a method for manufacturing polymer/metal hybrid structure is presented in which traditional plastic injection machine was converted to plastic injection forming (PIF). In this method, deforming of the metal and adhering the metal to the polymer is done in one step. In the experimental study, a special mold within rectangular cavity was used during PIF process. Aluminum plates of different thicknesses were used as the metal parts of the structure. The injected polymers were pure polystyrene and elastomer-added polystyrene. The deformability of the Al plates was examined under different injection pressures. In order to provide adhesion between metal and polymer, an adhesive of elastomeric nature was applied on the metal plate prior to injection molding. Bending test was applied to determine the flexural strength and maximum deflection of the polymer/metal hybrid structures. The obtained results were satisfactorily acceptable in improving the method for designing and manufacturing polymer/metal hybrid structures in one step.