Hydroxyapatite (HA) containing gold (Au) nanoparticles was synthesized for the biomedical applications. The morphology, structure and thermal properties of the HA containing Au nanoparticles were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), Fouriertransform infrared spectroscopy (FT-IR) and thermogravimetry (TGA). XRD patterns clearly revealed the formation of HA-Au composite nanoparticles. TEM observation showed that the Au nanoparticles had an average size of 5 nm and were incorporated into HA powder very well. Bactericidal activity of HA-Au with Au nanoparticles immobilized in HA was investigated. The adhesion, viability and proliferation properties of HA containing Au nanoparticles and the differentiation of osteoblast were studied for in vitro cell compatibility of the HA containing Au nanoparticles. Our results showed that HA containing Au nanoparticles were cytotoxic to the human osteoblastic cells. Copyright © 2011 American Scientific Publishers All rights reserved.