Corticosteroids have been used by many spine surgeons in the postoperative management of lumbar disc surgery patients. The potential side effects of these medications are significant, and yet there is little information available either supporting or contraindicating their use in the postoperative setting. This prospective, randomized double-blind study was designed to assess the effectiveness of the corticosteroid dexamethasone in decreasing postoperative pain and hospital stay after primary lumbar disc surgery. The patients' pain status was assessed both preoperatively and postoperatively by a standard pain questionnaire and pain drawing. Each patient's response to the questionnaire and pain drawing, as well as his usage of narcotics and days of postoperative hospitalization, were recorded and analyzed. Dexamethasone was shown to have a significant and selective effect on reducing leg pain postoperatively, while also significantly reducing the usage of injectable narcotics and shortening the postoperative hospital stay.