Twelve patients who had undergone osteosynthesis with a metal plate combined with a frozen homoplastic bone graft for the treatment of fractures or pseudarthrosis were subjected to bone scintigraphy with 99 Tc MDP. This investigation showed the graft to be a site of early and specific accumulation of the tracer. This finding supports early colonization of the graft by vascular structures and osteoblastic cells. In view of the small number of cases studied and our incomplete knowledge of the metabolic processes involved these considerations must remain hypotheses but given the excellent clinical results obtained, the relationships between homoplastic bone and host bone merit further investigation.