Background: A little data is known regarding relationship between the amount of alcohol consumption and vasospastic angina. We evaluated the impact of alcohol drinking pattern on significant coronary artery spasm (CAS) as assessed with intracoronary acetylcholine (Ach) provocation test. Methods: A total 793 consecutive patients [pts, men, 617(67.5%), mean age 50.56짹11.8 years] who underwent coronary angiography with acetylcholine (Ach) provocation test were enrolled for the study. Ach provocation test was done by injecting incremental doses of 20, 50, 100 ug into the left coronary artery. Study population were divided into two groups; the light to moderate alcoholics defined as average daily consumption of ethanol less than 30g/day whereas the heavy alcoholics consumed more than 30g/day . Results: Baseline clinical characteristics were similar except that heavy alcoholics were more men (95.1% vs.74%, P<0.001), smokers (55.6% vs. 40.5%, P<0.001), hypertensive (48.6% vs. 38.4%, P=0.023), diabetic (16.7% vs. 9.4%, P=0.011), whereas moderate alcoholics were more dyslipidemic (20.2% vs. 8.3%, P=0.001). Major results of Ach tests were similar between the 2 groups except for the heavy alcoholics showed higher incidence of response to lower Ach dose (A1, 20 ug) while chest pain was more frequent in moderate alcoholics in both univariate and multivariate analysis (Table). Conclusions: There was no difference between the light to moderate and the heavy alcoholics regarding CAS as assessed with Ach provocation test except for significant response to lower Ach dose in heavy alcoholics & more chest pain in moderate alcoholics. The heavy alcoholics may more vulnerable to Ach provocation test but needs clinical implication.