The unique biocompatible and wear resistant nature of ultrahigh molecular weight polyethylene (UHMWPE) makes it a suitable material for load bearing applications in total joint replacements (TJR). However, oxidation induced wear is a common cause limiting the life span of implants. Hence, Vitamin-E, a common antioxidant, is added to prevent the wear loss due to oxidation of UHMWPE. In addition, Hydroxyapatite does improve the toughening mechanisms occurring in the polymer matrices. Hence, in this study, a novel hydroxyapatite (HA) nanoparticles reinforced Vitamin-E doped UHMWPE nanocomposites (UHMWPE-E/HA) were developed here in this work. The HA concentration was varied between 0.5 - 3 wt.% and optimum wt% is reported. The mechanical and thermal properties were investigated thoroughly using an array of characterizations. Particularly, a considerable improvement in fracture toughness (K_IC) was obtained. Detailed examination of fractured surfaces was performed to understand the effect of HA reinforcement on fracture toughness of UHMWPE-E/HA nanocomposites.