Using a vital microscopic method, it has been possible to follow the vascular changes and bone remodelling in the same bone graft from the time of transplantation till one year afterwards. Grafts which received their first vessel early (5-9 days after grafting) contained vital bone and a vivid blood circulation one year after transplantation. Grafts which received their first vessel late (17-29 days after grafting) were only partly revascularized after one year and contained islands of dead bone. Minimal surgical trauma to both graft and the host bed is important for early revascularization of the graft, and, therefore, also contributes to a more complete incorporation of the graft.