The hydroxyapatite, obtained by chemical synthesis, is the main inorganic compound of bones and is very important due to its biocompatibility with the human organism to which it can directly adhere. There are numerous synthesis methods used at present because one has the purpose of obtaining a compound with the Ca/P atomic ratio as close to the theoretical one as posible, that is of 1.67. Two processes for obtaining hydroxyapatite of stoichiometric composition, the hydrothermal process and respectively microwave heating, were studied. Hydroxyapatite ceramic biocompatibility was demonstrated by cell viability tests as well as by scanning and fluorescence microscopy.