In the field of orthopaedic care, bioimplants play a crucial role in advancing human health. The interaction between bone and implant significantly impacts the healing process, with surface characteristics influencing the behavior of mesenchymal stem cells and their integration with surrounding tissue. Recent advancements have explored the use of nanoparticle surface modifications to enhance the biocompatibility and effectiveness of orthopaedic implants. This study proposes investigating the effectiveness of coating Stainless Steel 316L orthopaedic implants with zinc oxide (ZnO) nanoparticles to improve their biocompatibility, osseointegration, and durability. The research aims to evaluate the physicochemical properties, cytocompatibility, wear rate, and in vitro performance of ZnO nanoparticle-coated Stainless Steel 316L substrates, with the intention of improving orthopaedic operation patient outcomes and implant durability. The hydrothermal method was utilized to synthesize zinc oxide nanoparticles, which were subsequently characterized for composition, crystallinity, and morphology using various analytical techniques such as X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis, supported by elemental mapping. Analysis revealed that the synthesized nanoparticle exhibited a spherical shape with an average diameter of approximately 18 nm. The coating of ZnO nanoparticles onto Stainless Steel 316L substrates was achieved through the utilization of the spin coating technique, as confirmed by SEM images. Cell viability assessments employing the MTT assay were carried out to assess the cytocompatibility of the synthesized ZnO nanoparticles, both when coated and uncoated onto Stainless Steel 316L substrates, against the NIH-3T3 mouse embryonic fibroblast cell line. Results indicated a significant increase of 24.48% in cell viability for ZnO nanoparticles-coated Stainless Steel 316L substrates compared to uncoated ones. Furthermore, wear and friction resistance were assessed employing ball-on-disc tribometer under various conditions, revealing a substantial improvement in the performance of ZnO nanoparticles-coated Stainless Steel 316L substrates for orthopaedic applications