Mechanical properties and manufacturing processes of Glass Fiber/Polypropylene (GF/PP) composites for application of flexible internal long bone fracture fixation plates have been investigated. PP/Short Chopped Glass Fiber (PPSCGF), PP/Long Glass Fiber (PPLGF) and PP/Long Glass Fiber Yarn (PPLGFY) were used in fabrication of the fixation plates. The PPSCGF and PPLGF plates were made by the heat-compressing process and Three-dimensional (3D) printing method was used to make the PPLGFY ones. The values of Young’s modulus, tensile strength, flexural modulus and strength, and impact strength of the PPSCGF in the fiber longitudinal direction were found to be [Formula: see text]GPa, [Formula: see text]MPa, [Formula: see text]GPa, [Formula: see text]MPa and [Formula: see text]kJ/m2, respectively. Where, these values for the PPLGF were to [Formula: see text]GPa, [Formula: see text]MPa, [Formula: see text]GPa, [Formula: see text]MPa, and [Formula: see text]kJ/m2 and for the PPLGFY were to [Formula: see text]GPa, [Formula: see text]MPa, [Formula: see text]GPa, [Formula: see text]MPa and [Formula: see text]kJ/m2. These have been found to be in close agreement with the human bone properties. Furthermore, the strength and modulus values of the plates were reasonable to be used as a bone implant applicable for bone fracture reconstructions. Hence, the study concluded that the GF/PP composites are useful for load-bearing during daily activities and would be recommended as a choice in orthopedic fixation plate applications. It will help the researchers for development of new fixation designs and the clinicians for better patient’s therapy in future.