Background: Transient left ventricular (LV) ballooning syndrome is defined as a syndrome consisting of reversible LV ballooning in the absence of angiographically significant coronary artery stenosis. Although short-term outcomes are excellent, there are no data regarding long-term prognosis. We investigated long-term prognosis of this syndrome. Methods: We evaluated 87 patients who were diagnosed of transient LV ballooning syndrome in our hospital from 1997 to 2007. Transient LV ballooning syndrome was defined as an acute onset of a regional wall motion abnormality in the left ventriculogram or echocardiogram without significant stenosis in the coronary angiogram. We got information about patients in person, and the cause of death registry was informed by phone call from patients��� family. Results: During mean follow-up of 40.65 짹 29.16 months, 19 (21.8%) patients died. Long-term non-cardiac mortality rate was 21.8 % and cardiac mortality rate was 0 %. In-hospital non-cardiac mortality rate was 10.3 % and in-hospital cardiac mortality rate was 0 %. Of those 19 patients who died, 8 patients died of malignancy, 3 patients died of pneumonia, 3 patients died of brain stroke, 3 patients died of sepsis, 1 patient died of diabetes mellitus complication, and 1 patient died of chronic lung disease. Long-term mortality was associated with diabetes mellitus (p=0.049), smoking (p=0.019) but, not associated with age, sex, preceding physical stress, preceding emotional stress, post-operative states, chest pain, dyspnea, accompanying pulmonary edema, accompanying shock, angiotensin-converting enzyme inhibitor use, beta blocker use, hypertension, rhythm abnormality, ST elevation, Q wave, T wave inversion, cardiac marker levels, LV ejection fraction, regional wall motion abnormality, and improvement of regional wall motion abnormality on follow-up echocardiogram. Conclusions: The overall prognosis of transient LV ballooning syndrome seemed to be favorable. Because abnormality in the coronary circulation is not related to the etiology and in most patients, ventricular function improves with conservative treatment, most deaths are associated with comorbid conditions, not with cardiovascular complications.