At least 250,000 spinal fusions are performed in the United States each year, nearly all requiring implantation of bone graft material. The preferred technique for most of these operations is the transplantation of structured or morcellized autologous corticocancellous bone from the iliac crest. Further, because of the increasing frequency of spinal fusion surgery during the 1990s, arthrodesis of the spine has become the most common reason for autologous bone graft harvest. This article reviews the current clinical status of autogenous bone grafts and alternative materials in spinal fusion surgery.