Objectives: Purpose of our study was to determine if homocysteine plasma levels are related to the risk of in-stent restenosis after percutaneous coronary stent implantation in de novo lesions. Background: The putative role of homocysteine as a predictive cardiovascular biomarker of coronary artery disease is well established. The impact of homocysteine levels in the development of in-stent restenosis, however, is controversially discussed. Methods: A total of 177 patients with stable angina pectoris undergoing stent implantation in coronary de novo lesions were included. Laboratory determination comprised blood sample evaluation for homocysteine and other conventional risk factors before baseline coronary intervention and prior to six months control catheterization. Binary restenosis, late lumen loss, and late loss index after six months were assessed by quantitative coronary angiography. Endpoints included target lesion and target vessel failure, homocysteine levels as well as major adverse cardiac events. Results: There was a significant correlation between the length of the implanted stent(p< 0.006), the percentage of stenosis(p< 0.003) and the pre-interventional luminal diameter(p< 0.0001) with late loss index. Linear regression analysis demonstrated no significant impact of the initial or six months homocysteine levels on angiographic restenosis, late lumen loss, or late loss index. Conclusions: In contrast to homocysteine levels, luminal diameter, stent length and percentage of stenosis correlated with the appearance of restenosis. Taking our data into consideration, we hypothesise that homocysteine may not serve as a safe and independent biomarker of in-stent restenosis after a six months period following percutaneous coronary stenting. Objectives: Purpose of our study was to determine if homocysteine ​​plasma levels are related to the risk of in-stent restenosis after percutaneous coronary stent implantation in de novo lesions. Background: The putative role of homocysteine ​​as a predictive cardiovascular biomarker of coronary artery disease is well established. The impact of homocysteine ​​levels in the development of in-stent restenosis, however, is controversially discussed. Methods: A total of 177 patients with stable angina pectoris undergoing stent implantation in coronary de novo lesions were included. evaluation for homocysteine ​​and other conventional risk factors before baseline coronary intervention and prior to six-month control catheterization. Binary restenosis, late lumen loss, and late loss index after six months were assessed by quantitative coronary angiography. Endpoints included target lesion and target vessel failure, homocysteine ​​levels as well as major adverse cardiac events. Results: There was a significant correlation between the length of the implanted stent (p <0.006), the percentage of stenosis (p <0.003) and the pre-interventional luminal diameter Linear regression analysis demonstrated no significant impact of the initial or six months homocysteine ​​levels on angiographic restenosis, late lumen loss, or late loss index. Conclusions: In contrast to homocysteine ​​levels, luminal diameter, stent length and percentage of stenosis correlated with the appearance of Taking our data into consideration, we hypothesise that homocysteine ​​may not serve as a safe and independent biomarker of in-stent restenosis after a six months period following percutaneous coronary stenting.