Novel formulations of nano-hydroxyapatite (nano-HAp) and nano-HAp/chitosan composites have attracted much attention in these last years. The use of natural chitosan is found to be potential for fabrication of modified nano-HAp with many biomedical applications such as orthopedic, osteoconductive, dental and drug delivery applications. This review summarizes the different techniques employed for the elaboration of HAp nanoparticles and the effect of the incorporation of HAp with chitosan on the fabrication of nano-HAp composite and on their physical properties. We discuss the effects of the reaction conditions such as reaction time, temperature, pH, solvent nature, surfactants, and concentration of reactants on crystallinity, particle size, morphology and properties of nano-HAp composite. The nano-HAp progress and the present status of HAp (either experimental or theoretical results) have been reviewed.