Fracture healing is a specialized form of the reparative process that the musculoskeletal system undergoes to restore skeletal integrity. This biologic process is a consequence of a complex cascade of biologic events that result in the restoration of bone tissue, allowing for the resumption of musculoskeletal function. Several growth-promoting substances have been identified at the site of skeletal injury and appear to play a physiologic role in fracture healing. This article reviews the effects of these osteoinductive growth factors on bone healing as elucidated by both preclinical in vivo fracture and diaphyseal defect healing models.