Background: It has been reported that coronary artery spasm (CAS) event can be followed by an increase in fibrinopeptide A level. However, it is still unclear whether the acetylcholine (Ach) induced CAS is associated with higher baseline fibrinogen level. Method: Between Nov 2004 and June 2009, a total 906 patients (pts) presented with suspected vasospasgtic angina underwent coronary angiography and Ach provocation test (20, 50 and 100 µg to left coronary artery) and also baseline fibrinogen level was measured. Pts with diffuse or focal significant spasm of more than 70% narrowing were grouped as spasm (+) group (n=525 pts) while pts with no or insignificant spasm were grouped as spasm (-) group (n=381 pts). We investigated whether pts with spasm (+) group have different fibrinogen level as compared with that of spasm (-) group. Results: Pts in spasm (+) group were more elderly, male gender, higher incidence of peripheral vascular disease (PVD) and more usage of calcium channel blocker (CCB) than those of spasm (-) group. Fibrinogen level was not found to be an independent predictor of Ach-induced CAS (Table). Conslusion: Baseline serum Fibrinogen level before Ach provocation test was not closely associated with the Ach provocation test results regardless of presence of significant CAS. Further study will be needed to confirm the association of fibrinogen level with significant CAS.