The early vascular response is essential for the normal progress of fracture healing and fracture site blood flow has been shown to reach a peak in the first two weeks after injury. Angiogenesis is an important step in this response as new vessel formation is necessary to vascularize the fracture haematoma and the fracture gap. Changes in serum levels of a low molecular weight endothelial stimulating angiogenic factor (ESAF) have been previously reported in a group of four patients with tibial fractures. In this group, ESAF levels were measured on three occasions only and at different time intervals. We present a more detailed profile of serum ESAF level changes in the first 14 days after the fracture.