Based on the favorable clinical results in acute spinal cord injury, high-dose methylprednisolone at an intravenous loading dose of 30 mg/kg followed by a continuous infusion of 5.4 mg/kg/h for 24 or 48 hours has been adopted for the treatment of acute traumatic optic neuropathy (TON). Although there is anecdotal evidence of the efficacy of high-dose corticosteroid in this condition, there are no prospective, randomized trials to attest to its benefit. On the other hand, the largest retrospective study showed no benefit of high-dose corticosteroid treatment of TON. Moreover, subsequent study of such treatment of acute spinal cord injury has disclosed that the clinical benefit is modest and that treatment is actually harmful if administered more than eight hours after injury. A recently reported placebo-controlled randomized clinical trial of high-dose corticosteroids in head injury was stopped prematurely because of a significantly greater mortality in the corticosteroid-treated patients. Recent experimental studies suggest that methylprednisolone may be harmful to the optic nerve. Considering this clinical and experimental evidence, there is no basis for treating TON with high-dose corticosteroid.