Hydroxyapatite (HA)-coated metal implants were developed in order to capitalize on the excellent biological properties of HA, and minimize the potential for mechanical failure of the HA in vivo. Results of implantation studies suggest that synthetic HA is osteoconductive (enhances local bone healing) and becomes osteointegrated (forms an intimate bond with bone). HA-coated prostheses are currently being evaluated for use in cementless total joint arthroplasty. The purpose of this article is to review the experimental studies leading to the development of HA-coated orthopedic devices, and to summarize the current status of clinical studies. Finally, the concerns and future directions for HA-coated implants are addressed.