We performed a randomised single blind trial of high-dose dexamethasone as an adjunct to radiotherapy in patients with metastatic spinal cord compression from solid tumours. After stratification for primary tumour and gait function, 57 patients were allocated randomly to treatment with either high-dose dexamethasone or no steroidal treatment. Dexamethasone was administered as a bolus of 96 mg intravenously, followed by 96 mg orally for 3 days and then tapered in 10 days. A successful treatment result defined as gait function after treatment was obtained in 81% of the patients treated with dexamethasone compared to 63% of the patients receiving no dexamethasone therapy. Six months after treatment, 59% of the patients in the dexamethasone group were still ambulatory compared to 33% in the no dexamethasone group. Life table analysis of patients surviving with gait function showed a significantly better course in patients treated with dexamethasone (P < 0.05). Median survival was identical in the two treatment groups. Similar results were found in subgroup analysis of 34 patients with breast cancer as the primary malignancy. Significant side-effects were reported in 3 (11%) of the patients receiving glucocorticoids, 2 of whom discontinued the treatment. We conclude that high-dose glucocorticoid therapy should be given as adjunct treatment in patients with metastatic epidural spinal cord compression.