Introduction: Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome. Pathogenesis of SCAD is certainly unclear, female, peripartum period, atherosclerosis is known to increase the risk. The various connective tissue disease is known to be associated with SCAD. However, the relevance of the Fragile x syndrome have not been reported. We report a case of experience in the SCAD women with fragile x syndrome. Case Report: A 45 years old female patient visited the emergency room due to anterior chest pain. She did not have any coronary risk factor. She had informed that she is fragile X syndrome carrier. Electrocardiography showed the ST segment elevation in the V2, V3, V4 leads. Cardiac enzymes were within normal ranges at the time of arrival. Coronary angiography revealed a linear coronary artery dissection from middle-to-distal left anterior descending artery(LAD). Intravascular ultrasonography(IVUS) showed an intimal tear middle to the dissection site in the LAD and an intramural hematoma. Percutaneous coronary angiography and DES stent insertion was performed. After stent insertion, resolution of the intimal dissection area was confirmed by IVUS and coronary angiography Conclusions: We had experienced SCAD patients with fragile x syndrome. Relationship between fragile x syndrome and SCAD is unclear. However, In women with no evident coronary risk factor had experienced SCAD. Therefore, In individuals with fragile x syndrome, it will require studies on the relationship between the SCAD.