OBJECTIVE Spinal cord ischemia remains a serious complication of thoracoabdominal aortic aneurysm surgery. Coenzyme Q10, a potent antioxidant, has been reported to exert a neuroprotective effect. In the present study, we evaluated the effect of coenzyme Q10 pretreatment on spinal cord ischemia-reperfusion injury. METHODS Male Sprague-Dawley rats were treated with either 300 mg/kg coenzyme Q10 (CoQ10 group, n = 12) or saline (control and sham groups, n = 12 for each group) for 5 days before ischemia. Spinal cord ischemia was induced in the control and CoQ10 groups. Neurological function was assessed using the Basso-Beattie-Bresnahan (BBB) motor rating scale until 7 days after reperfusion, and then the spinal cord was harvested for histopathological examinations and an evaluation of malondialdehyde level. RESULTS On post-reperfusion Day 1, the CoQ10 group showed higher BBB scores compared with those in the control group, although the difference was not significant. However, on Day 2, the CoQ10 group showed a significantly higher BBB score than the control group (14.0 [10.3-15.0] vs 8.0 [5.0-9.8], median [IQR], respectively; p = 0.021), and this trend was maintained until Day 7 (17.5 [16.0-18.0] vs 9.0 [6.5-12.8], respectively; p < 0.001). Compared with the control group, the CoQ10 group had more normal motor neurons (p = 0.003), fewer apoptotic changes (p = 0.003) and a lower level of tissue malondialdehyde (p = 0.024). CONCLUSIONS Pretreatment with 300 mg/kg coenzyme Q10 resulted in significantly improved neurological function and preservation of more normal motor neurons.