Background The disease course of stress induced cardiomyopathy (SIC) is usually benign but could be fatal in some cases. However, the prognostic factors to predict worse outcome are not well established. We analyzed APACHE (Acute Physiology and Chronic Health Evaluation) II score, a well-known disease severity classification system for critically ill hospitalized adults, to assess its predictability for worse prognosis in patients with SIC. Methods Twenty-nine consecutive patients with SIC were studied and followed up prospectively during hospitalized days. Clinical factors including APACHE II, coronary angiogram, and echocardiography were analyzed in all patients. Results Of 29 patients, 22 (76%) were women. Mean age was 64짹16 years. Most common presentation was chest pain (24%). All patients showed normal coronary angiogram. Initial echocardiographic left ventricular ejection fraction(EF) was 42.5짹9.3 % and wall motion score index (WMSI) was 1.9짹0.3. Only 3 patients among 7 men were expired during the follow up hospitalized days. APACHE II score was significantly higher in the died 3 patients than the alive patients (22.7짹2.1 vs 11.2짹6.4, p<0.001). Among various clinical variables, only APACHE II score and N-terminal pro-B-type natriuretic peptide were correlated well with the duration till recovery of echocardiographic wall motion but not the case for echocardiographic EF nor the WMSI. Conclusions The prognosis of the SIC did not depend on heart function but on physical condition of patient in terms of APACHE II. Assessing APACHE II could be helpful to expect the worse prognosis in patients with SIC.