A prospective double-blind clinical trial was performed on 161 patients to determine the effectiveness of high-dose steroid therapy in patients admitted comatose after a non-missile-related head injury. Patients were randomized into a high-dose dexamethasone phosphate group and a placebo group. The initial dose of 100 mg of dexamethasone was administered within 6 hours of the accident. For statistical analysis, a sequential test was chosen, using survival at 1 month as a basic criterion of effectiveness. No significant difference was found in the 1-month survival rate or in the distribution of outcome after 6 months, either within the group as a whole, or in subgroups with varying severity of brain damage on admission. The authors conclude that dexamethasone in high doses has no statistically significant effect on morbidity or mortality in head-injured patients who are comatose on admission.