The present study was performed to evaluate the effect of duration of acute spinal cord compression on tissue lipid peroxidation in rats. A clip compression method (1) was used to produce acute spinal cord injury Rats were divided into 3 groups, each consisting of 10. At 1 hour after trauma all rats were sacrificed, and MDA content of the injured spinal cord segment was measured. The tissue MDA contents were 3.922 mu molMDA/gww in group 1 (control), 10.192 mu molMDA/gww in group 2 (30 seconds compression), and 12.147 mu molMDA/gww in group 3 (60 seconds compression). These results demonstrate that the length of duration of compression significantly enhances lipid peroxidation. Our study supported the view that persisting compression may cause progression of secondary mechanisms which may irreversibly eliminate any potential for recovery.