OBJECTIVE: Spinal epidural fi brosis is commonly seen after laminectomy. There is not yet proven any agent preventing fi brosis in clinical usage. We used diclofenac sodium and diltiazem, which are fi brosis inhibitors. METHODS AND MATERIALS: 40 rats were divided into four groups of equal numbers: control, diclofenac sodium, diltiazem, and diclofenac sodium + diltiazem. Laminectomies were performed at L5 and L6. After a 4 week period, the rats were decapitated and the vertebral column blocks were removed for histopathologic examination. Fibrosis percentage, spread of fi brous regions, and fi broblast numbers were evaluated in each group and compared between the groups. RESULTS: The distribution of epidural fi brosis density, percentage of fi brosis, and distribution of fi broblasts in the diclofenac sodium + diltiazem group were signifi cantly lower than in the other groups. The fi broblast numbers of the diltiazem, and diclofenac sodium + diltiazem groups were signifi cantly lower than in the other groups. CONCLUSION: Diclofenac sodium + diltiazem used together provided better outcomes because each of them prevented fi brosis via different ways, probably through synergistic action (Tab.