Nanocrystalline carbonated hydroxyapatite was produced through hydraulic conversion of calcium phosphate cement in simulated body fluid (SBF) and then heated in a microwave oven at 1000-1250 °C. The phase composition and microstructures were evaluated, before and after the thermal processing, using XRD and SEM, respectively. Total porosity and bending strength of the samples were also tested. Proliferation and morphology of osteoblastic cells on samples were evaluated using MTT method. Limited growth of apatite crystals was observed by the thermal treatment in which the samples exhibited a crystal size of ~ 150 nm at heating temperature of 1250 º. Based on the results, the microwave irradiation led to a little change in phase composition of carbonated apatite and slight amount of β-TCP phase was found together with large amount of apatite. The sample irradiated at 1250 °C formed more dense material having bending strength value up to 130 % that of unheated sample. The in vitro cell studies showed that the microwave irradiated samples could provide adequate cell proliferation and attachment.