A novel one-step preparation of magnesium particles and Pluronic F127 incorporated with calcium sulfate hemihydrate (CSH) and nano-hydroxyapatite (nHA) ready to use injectable or moldable beads was developed for bone tissue regeneration applications. The nanocomposite showed setting time less than 15 min, very good injectability (75–85%) and good mechanical strength (52–80 MPa). Samples immersed in SBF showed controlled degradation (40–45% reduction in weight) in 28 days. The nanocomposite bone graft was cytocompatible against MG63 osteosarcoma cells and increased the osteogenic gene expression by 2–3 folds. These results indicate that it can be a potential defect filling biomaterial for bone tissue regeneration at the fracture site. © 2018 Elsevier Ltd