Background and Objectives: Endothelium-dependent vasodilation in impaired in chronic smokers and patients with variant angina. The aim of this study is to evaluate whether a three-month smoking cessation can improve endothelial function in chronic smokers with variant angina. Methods: In 23 chronic smokers with variant angina (47.0짹6.8years, 23 males), the endothelial functions that were defined by flow-mediated endothelium dependent vasodilation (FMD) of the brachial artery, as well as the number of carboxyhaemoglobin (COHb) isolated from peripheral blood, were determined at baseline and also at 3 months after taking smoking cessation. COHb can estimate patients smoking state and might be relevant in cardiovascular risk assessment. Results: The changes of the clinical characteristics and the labolatory findings were not different between baseline and at 3 months after smoking cessation. The FMD was significant improved after 3 months (5.2짹2.6% vs. 6.5짹2.3%, p=0.048). The COHb was significant decreased after 3 months (3.8짹1.3% vs. 1.8짹1.1%, p<0.001). The FMD was correlated with the COHb level before treatment(r=-0.38, p=0.039) and after 3 months (r= -0.41, p= 0.023). Conclusion: The FMD is reduced and COHb is increased in chronic smokers with variant angina. Smoking cessation induces improvement of the FMD and decreases the level of COHb. A smoking cessation may be effective for reducing the cardiovascular event in chronic smokers with variant angina.