Studies of orthopaedic implant failures have shown that mechanical failure of an implant almost exclusively occurs at the biomaterial-tissue interface. Hydroxyapatite (HA) mimics the behavior of natural bone, and provides a strong, long-lasting adhesive interface between a bone replacement implant and the surrounding tissue. Currently, thin film HA is not commonly used because it contains defects, porosity, and cracks. Delamination of the hydroxyapatite film and formation of hydroxyapatite particles may lead to implant wear and loosening. Furthermore, the coating also acts only as a temporary barrier to ion release from the bulk biomaterial. One method to improve the biocompatibility of a bioactive coating is to strengthen the microstructure of the hydroxyapatite coating through the placement of a DLC (hydrogen-free diamondlike carbon) interlayer. DLC coatings possess properties close to diamond in terms of hardness, atomic smoothness, and chemical inertness. We have developed a diamondlike carbon/HA bilayer, in which the bilayer surface (HA) is bioactive and the interlayer (diamondlike carbon) is biocompatible, wear resistant, and corrosion resistant. We have successfully deposited nanocrystalline hydroxyapatite and DLC films by ablating a hydroxyapatite target and a graphite target using a KrF laser. Surface morphology was studied using SEM; interfacial structure was studied using TEM, and HA phase microstructure was studied using XRD. The DLC/nanocrystalline HA bilayer material is potentially useful for several orthopedic implant designs.