OBJECTIVE The aim of the present study was to evaluate the effect of tissue-engineered constructs on repair of large segmental bone defects in goats. METHODS Allogenic demineralized bone matrix (aDBM) was seeded with autologous marrow stromal cells (aMSC) for seven days to construct DBM-MSC grafts prior to implantation. 24 goats were randomly divided into three groups (eight in each). In each group, 3 cm diaphyseal femoral defects were created unilaterally, and subsequently filled with the DBM-MSC grafts, DBM alone and an untreated control, respectively. Radiological analysis and biomechanical evaluation were performed at 12 and 24 weeks after operation. RESULTS Obvious increases in radiological scoring and biomechanical strength were found in the DBM-MSC group when compared to the DBM group. X-ray examination showed excellent bone healing in the DBM-MSC group, whereas only partial bone repair was seen in the DBM group, and no healing in untreated controls. Histologically, a tendency to bone regeneration and remodeling was far more obvious for the DBM-MSC group than the DBM only and untreated controls. CONCLUSIONS Our results strongly suggest that transplantation of bone MSC within a DBM could have advantages for the bone repair of large segmental defects.