Forty-four patients with metastatic brain neoplasms received glycerol instead of corticosteroids during periods of brain irradiation. Headache, nausea, and vomiting were controlled in more than 90% of symptomatic patients, while paralysis, confusion, and papilledema improved in 55% to 80%. Patients with minimal or no symptoms remained stable. Patients with moderate or severe symptoms had significant improvement during the first week and substantial improvement during the second week of treatment. Glycerol did not induce immunosuppression when administered in combination with radiotherapy and chemoimmunotherapy. Patients with malignant melanoma had longer survival when treated with glycerol instead of corticosteroids.