Autologous bone graft has been used in the treatment of complex bone defects for more than a century. Morbidity associated with the harvest of this bone graft has led orthopaedic surgeons to seek alternative therapies in the treatment of long bone non-unions. The aim of this study was to determine whether the use of demineralised bone matrix as a bone healing adjunct improves clinical outcomes in adult patients with long bone non-union. A systematic search was carried out of the peer-reviewed English language literature to identify all relevant studies. The search strategy returned a total of 47 studies. Five of these studies were relevant to the research question. The studies were critically assessed and where appropriate combined in a meta-analysis. 4 non-comparative studies and one comparative study were reviewed. An overall estimate of the rate of union for the five studies was 86% (95%CI: 71–94%). The one comparative study demonstrated the relative risk (RR) of healing was not significantly better than in patients treated with autologous bone graft; RR=1.03 (95%CI 0.96–1.12). There are limited data to support the use of demineralised bone matrix in the treatment of long bone non-union. Demineralised bone matrix is likely to be similarly effective to other treatments in the management of non-union. This study confirms the clinical and ethical requirements to proceed with a randomised controlled trial to test the effectiveness of this intervention.