Bioactive and low cytotoxic three dimensional nano-hydroxyapatite (nHAp) and aligned carbon nanotube oxide (a-CNTO) composite has been investigated. First, freestanding aligned carbon nanotubes porous scaffold was prepared by large-scale thermal chemical vapour deposition and functionalized by oxygen plasma treatment, forming a-CNTO. The a-CNTO was covered with plate-like nHAp crystals prepared by in situ electrodeposition techniques, forming nHAp/a-CNTO composite. After that nHAp/a-CNTO composite was immersed in simulated body fluid for composite consolidation. This novel nanobiomaterial promotes mesenchymal stem cell adhesion with the active formation of membrane projections, cell monolayer formation and high cell viability.