Objective : A prospective, randomized, controlled clinical study is performed to verify the effectiveness of epidural dexamethasone-soaked gelatin sponges to reduce postoperative pain following lumbar microdiscectomy. Methods : Twenty-three patients (10 men and 13 women) undergoing lumbar microdiscectomy were included. Five pieces of gelatin sponge measuring $1{ imes}1cm$ [Gelfoam; Pharmacia & Upjohn. Kalamazoo, MI, USA], soaked with either 5mg dexamethasone or an equal amount [2mL] of saline, were left on the decompressed nerve root after unilateral hemilami-nectomy, flavectomy and discectomy. Results : Subjective visual analog scale[VAS] scores of leg pain in the dexamethasone group on the first, third and first postoperative days [2.5, 2.5, 1.7, respectively] were significantly lower than in the control group [5.0, 4.8, 3.6][P<0.05]. No side effects related to the dexamethasone-soaked gelatin sponges were observed. Conclusion : The intraoperative application of dexamethasone-soaked gelatin sponges during lumber microdiscetomy can provide effective-postoperative analgesia without complications.