Background and Objectives:Hyperhomocyt(e)inemia has recently become to be one of the independent risk factors for ischemic heart diseases, although the role of hyperhomocysteinemia in restenosis following coronary intervention is unclear. The relationship between plasma homocysteine level and restenosis following coronary intervention was evaluated in Korean patients. Materials and Method:Eighty three patients underwent successful percutaneous coronary intervention (PCI) and the follow-up coronary angiographies were divided into two groups according to restenosis. The level of plasma homocysteine was compared between the groups with restenosis (n=35, M:F=27:8, 60.6±13.5 years) and without restenosis (n=48, M:F=40:8, 60.3±12.8 years). Results:The clinical manifestation, atherosclerosis risk factors except for hypertension, and coronary angiographic findings were not significantly different in patients with or without restenosis (p=NS). The value of homocysteine was 9.3±3.1 μmol/L in 35 patients with restenosis and 8.4±2.5 μmol/L in 48 patients without restenosis (p= NS). All 8 patients whose values of plasma homocysteine were more than 13 μmol/L, displayed angiographic restenosis. Plasma homocysteine was not an independent risk factor of restenosis by means of logistic regression analysis. Conclusion:Plasma homocysteine is not a potential risk factor of for restenosis following percutaneous coronary intervention. (Korean Circulation J 2001;31(6):560-566)