Although takotsubo cardiomyopathy (TTC) has been reported to have a favorable outcome, many complications may occur in the acute phase. Heart failure is the most common clinical complication in patients with TTC. We aimed to investigate determinants of secondary pulmonary hypertension (PH) in patients with TTC. This study consisted of 55 patients with TTC. Detailed echocardiographic measurements were taken, including pulmonary artery systolic pressure (PASP). PH was identified PASP >35 mmHg. The severity of mitral regurgitation (MR) was evaluated by measuring effective regurgitant orifice area (EROA). Follow-up echocardiography was performed in 45 patients (81.8%) within 4 weeks after initial presentation. All patients were stratified into PH or no PH (NPH) group (average PASP: 46.2 ± 6.7 vs. 29.8 ± 3.3 mmHg, P < 0.001); 25 patients (45.5%) were categorized into the PH group. Left ventricular (LV) volume, LV ejection fraction, and troponin I levels did not significantly differ between the two groups. Age and EROA were significantly greater in PH group than NPH group (age; 74.6 ± 9.1 vs. 63.5 ± 17.7, EROA; 0.22 ± 0.17 vs. 0.03 ± 0.05 cm(2) , all P < 0.01). The multivariate analysis revealed that age and EROA were independent predictors for PH in patients with TTC (all P < 0.001). PASP was significantly improved at follow-up compared to those at initial presentation (35.8 ± 8.4 vs. 30.3 ± 7.9 mmHg, P < 0.01). Age and the severity of MR were independent predictors for secondary PH in patients with TTC.