Abstract: Non-union is still one of the most common complications in orthopaedic practice. One major problem with the diagnostic management of fracture non-union is the definition or the criteria of non-union. The objective of this study is to determine the reliability of the Radiographic Union Scale for Tibial Fractures (RUST) score when used to assess bone healing in patients with femoral fractures treated with intramedullary SIGN nailing. Six observers were employed randomly, namely, three fellow orthopaedic consultants from a pool of six consultants and three orthopaedic residents in a tertiary government hospital, to assess the femur radiographs treated with intramedullary SIGN nailing using the RUST.