Polymeric biomaterials perform many different functions within the medical field, depending on their mechanical properties and the way they degrade. With regard to prostheses, the most commonly used types are the high density polyethylene (HDPE) and the ultra high molecular weight polyethylene (UHMWPE), which present several advantages over other materials and other types of polymers. In this project, the topological optimization of a HDPE femur endoprostheses will be performed using the finite element method in ANSYS 2020 R2 [1]. To achieve that, the linear static analysis of a body, with the thigh bone geometry, subjected to loads and boundary conditions will be initially performed. From the study of mechanical stress suffered by the femur during day-to-day activities, it will be selected which loading case to be used for the simulations. The resulting part must must meet the resistance criteria when submitted to the same conditions previously defined, even after its volume reduction. To check the fulfillment of this objective, the model will be validated, generating the static structural analysis module again, with the same boundary and discharge conditions applied initially, and observing the new stress responses in the optimized structure.