Crystalline hydroxyapatite thin coatings have been prepared using a novel opposing RF magnetron sputtering approach at room temperature. X-ray diffraction (XRD) analysis shows that all the principal peaks are attributable to HA, and the as-deposited HA coatings are made up of crystallites in the size range of 50-100nm. Fourier transform infrared spectroscopy (FTIR) studies reveal the existence of phosphate, carbonate and hydroxyl groups, suggesting that HA coatings are carbonated. Finally, in vitro cell culture experiments have demonstrated that murine osteoblast cells attach and grow well on the as-sputtered coatings. These results encourage further studies of hydroxyapatite thin coatings prepared by the opposing RF magnetron sputtering approach as a promising candidate for next-generation bioimplant materials.