Background : Rapamycin(sirolimus)-eluting stents are associated with reduced restenosis rates in animal studies and human trials. Oral everolimus( a macrolide of the same family as sirolimus) has been shown to inhibit in-stent neointimal growth. This study evaluated whether orally administered everolimus can reduce neointimal formation in balloon-injured rat carotid artery. Methods and Results : Oral everolimus (1.25mg/kg/day) or matching placebo was administered daily to 30 rats by oral gavage starting 3 days before balloon injury to 14 days after balloon injury. Treatment effects were assessed at 7 , 14 , and 28 days after injury. Oral everolimus group showed significant reduction in neointimal formation at 7, 14, 28 days after injury compared to the control group(Figure). However, after discontinuation of therapy, oral everolimus group showed considerable amount of neointimal formation at 28 days after balloon injury, and it was comparable to that of control group at 14 days after balloon injury. Conclusion : Oral everolimus significantly reduces neointimal formation in balloon-injured rat carotid artery, however short term treatment does not prevent neointimal formation at the investigated dose of 1.25 mg/kg/day.