Takotsubo syndrome has increasingly been recognized in the differential diagnosis of patients presenting with acute chest pain. Those affected are typically older women suffering after an emotional or physical stress. Normally it is a transient condition but complications including death have been reported. We reported a case of takotsubo syndrome who was initially diagnosed as acute coronary syndrome. The patient presented with typical angina, ST-T segment changes, and elevated high sensitive-troponin I. Coronary angiography showed normal coronary arteries. Transthoracic echocardiography revealed mild left atrial dilatation and left ventricle concentric hypertrophy, reduced left ventricle ejection fraction with circumferential hypokinetic, apical ballooning, systolic anterior motion, left ventricle outflow tract obstruction, and sigmoid septum hypertrophy. One month later, patient recovered and transthoracic echocardiography revealed improved heart anatomy and function. To differentiate takotsubo syndrome with other conditions, especially acute coronary syndrome, is crucial. Their clinical presentations are similar but the managements are different. The transthoracic echocardiography holds an important role in supporting the diagnosis of takotsubo syndrome.