Recently we reported that tumor necrosis factor-α (TNF-α) mRNA expression and the development of postoperative intimal hyperplasia (IH) is different in rat epigastric vein interposition graft, compared to femoral artery re-anastomosis. We evaluated whether a TNF-α suppressive agent, FR-167653 (Fujisawa Pharm. Co., Ltd., Osaka) could suppress IH or not. Eleven Lewis male rats (480±8g) were studied. The epigastric vein graft was interposed into the common femoral artery. They were divided into two groups: group FR (n=5) with 2.0μg/g of FR-167653, and group C (n=6) with same dose of saline instead of FR-167653. The intimal areas of vein grafts were measured at 4 weeks postoperatively. The mean intimal area in group FR was significantly decreased, compared with group C (0.160±0.057mm² vs. 0.434±0.045mm², p<0.01). These results suggest that the TNF-α suppressive agent FR-167653 may suppress the postoperative intimal hyperplasia that occurs on the interposition vein graft in rats.