In this study, the effect of free oxygen radicals on lipid peroxidation and the antioxidant role of alpha-tocopherol (vitamin E) in these reactions were investigated in haematoma fluid and venous blood samples in rabbits with femoral fracture. There were 21 male rabbits, divided into 3 groups. Conjugated dienes values (as optical density) were compared in venous blood of the rabbits in Group I taken preanaesthesia and after the onset of anaesthesia and the difference between these values proved to be insignificant (P > 0.05). A control group (Group 2) was given saline before fracture occurrence and the other group (Group 3) was injected with alpha-tocopherol 20 mg/kg intramuscularly. Venous blood samples and fracture haematoma fluids in both Group 2 and Group 3 were assayed biochemically. It was established that conjugated dienes values in fracture haematoma fluid in rabbits in the control group were higher than the values in the venous blood of the rabbits in the same group (P < 0.05). However, conjugated dienes values in the alpha-tocopherol injected group both in the haematoma fluid and in venous blood were reduced compared with those in the control group (P < 0.5). In view of the fact that ischaemia and reperfusion develop in fractured regions and that general body ischaemia develops following serious fractures of the extremities, we consider that prophylactic administration of antioxidants such as alpha-tocopherol may be beneficial in suppressing the destructive effects of free oxygen radicals in cells.