Pure and Mg(2+) & F(-) doped nano hydroxyapatites (HA) were synthesized by a precipitation method and sintered at 1100 degrees C to investigate their densification and structure. Different amounts of Mg(2+) and F ions were doped in to HAs. X-ray diffraction was used to identify the presence of phases And lattice parameters of HA and tri-calcium phosphates (TCP) present in the samples. Densification of HA was improved by the addition of these ions. In most of the doped samples, beta-tri-calcium phosphate (TCP) formation was observed as a second phase with the addition of Mg. Structure of the pure and doped samples were hexagonal and rhombohedral for HA and TCP, respectively.