The current study aims to examine the stress behavior along with the Knee Implant components namely femoral, tibial cushion, and the tibial insert where the femoral and tibial insert components are made of Ti–6Al–4V alloy and the tibial cushion component is varied with different polymer-based biomaterials like Ultra High Molecular Weight Polyethylene (UHMWPE), Poly-Ether-Ether-Ketone (PEEK) and Polymethyl Methacrylate (PMMA). A three-dimensional (3D) computer-aided design (CAD) of knee implant is prepared using Autodesk Fusion 360 modeling software. The static structural analysis is carried considering a load of 2000 N (3 times the body weight of an average 68 kg person). Three material models are used in which the femoral and tibial insert materials are kept constant and only the tibial cushion material is varied. The purpose of this study is to test the applicability of PEEK and PMMA bio-materials in the field of knee prosthetics using a numerical approach. The PEEK and PMMA materials are mostly used in spinal implants, dental implants, and hip replacement surgeries which need to verify using Finite Element Analysis (FEA). The static structural deformation and the von-Mises stress behavior of the femoral, tibial cushion, and tibial insert are analyzed and studied. The Material Model (MM-I) with a tibial cushion made of UHMWPE material, and the femoral and tibial insert made of Ti-6Al-4V alloy shows better stress behavior (Minimum stress generation) than the other material models. This study validates the reason for preference of UHMWPE material over any other biomaterial, for the tibial cushion component of a knee implant. © 2021