Background : Oxidative stress might be a role in atherogenesis and increased intake of antioxidant appear to be protective and modify neointimal formation. An antioxidant, probucol, prevents endothelial dysfunction and low density lipoprotein oxidation and also inhibits the secretion of cytokine by macrophages. We aimed to study 1) the effects of conventional doses of antioxidant(vitamin C, E and probucol) supplementation on serum level of antioxidant status, P-seletin, MCP-1, IL-6 and IL-10 and 2) the effects of antioxidant intake on in-stent restenois and 3) the correlation of the antioxidant status with in-stent restenosis. Methods : Total 90 patients with coronary artery disease have been enrolled in the study. The patients were assigned to control or antioxidant group (probucol; 500mg, vitamin C; 1000mg, vitamin E; 400mg). We performed follow up coronary angiography in 35 patients of antioxidant group and 36 patients of control group after 6 months of coronary bare metal stent implantation. We counted the stenotic lesions more than 50% of implanted stent lumen as a restenosis by quantitative coronary angiography. Baseline clinical characteristics, blood chemistry, other medication, blood pressure were not different between two groups. The serum levels of total antioxidant status were measured with RANDOX kit from RANDOX Lab using colorimetric method. The serum levels of P-seletin, MCP-1, IL-6 and IL-10 were measured with kits from R&D Systems using ELISA method. Results : The serum levels of total antioxidant status was not elevated in antioxidant group. Antioxidant supplementation did not change the serum levels of P-selectin, MCP-1, IL-6 and IL-10. The 6-month angiographic in-stent restenosis rate was 27% versus 30% (p=NS) with an associated late loss of 0.76짹1.01 mm versus 0.91짹1.00 mm(p=NS) for antioxidant group and control group. The serum levels of total antioxidant status did not correlate with the restenosis or late loss after stent implantation. Conclusions : Conventional doses of vitamin C, E and probucol did not elevate the serum level of antioxidant status and could not prevent in-stent restenosis after bare metal stent implantation.