Tissue engineering is a growing field where new materials are being developed for implantation into the body. One important area involves bone graft materials to replace areas of bone lost to trauma or disease. Traditionally, graft material may be harvested from the bone of the individual receiving the graft material. However, this requires an additional surgery and additional recovery. Bone also may be taken from others, or even cadavers, but this introduces biocompatibility problems as well as the risk of disease transfer. Ideally, a biocompatible material is sought that will act as a filler with appropriate mechanical strength, encourage bone healing, and degrade to allow new bone ingrowth without the risk of disease transfer. The present invention is a new composite bone graft material made from biocompatible poly(D,L-lactic-co-glycolic acid) (PLGA) and nano-sized hydroxyapatite particles exposed on its surface using a gas foaming particle leaching (GF/PL) method. A further embodiment of this invention involves coating this PLGA/hydroxyapatite biomaterial with an adherent, fast, uniform coating of a mineral such as apatite. The PLGA polymer portion of the composite provides sufficient mechanical strength to replace bone and is degradable over time to allow new bone tissue ingrowth. The incorporated hydroxyapatite particles increase the composite material's osteogenic properties by providing sites for tissue attachment and propagation. Finally, a uniform coating of mineral apatite on the surface of this novel biomaterial composite further enhances its osteogenic qualities.