Introduction: We report the case of a 62 year old patient, known with breast cancer with radical mastectomy, chemo- and radiotherapy and with cerebral ischemic stroke (MRI documented), under therapy with aromatase inhibitors. She was admitted with signs of heart failure appeared about a year and a half ago and significantly worsened in the last month. Methods: Trans esophageal and transthoracic echocardiography revealed grade II degenerative mitral regurgitation, but also grade III functional tricuspid regurgitation with moderate pulmonary hypertension. Right cavities were slightly dilated, but the right and left ventricular systolic function were preserved. No intracardiac thrombi were found. At that time, considering the symptoms of the patient, her neoplastic history, the echocardiographic signs, we raised the suspicion of pulmonary embolism. The chest contrast computed tomography confirmed the presence of intraluminal thrombi in lobar and segmental pulmonary arteries bilaterally. Results: Under injectable and oral anticoagulant therapy the patient’s evolution has been slowly favorable. Conclusions: In this case, we considered at least two causes for the occurrence of pulmonary thromboembolism: the malignant status and the long term antineoplastic hormonal therapy, without excluding each other. Long-term treatment was the main problem in this patient by bringing the judgment of the cardiologist and the oncologist together, each one with pros and cons for anticoagulant and hormonal antineoplastic therapy. The final decision was in favor of both therapies. The 6 months evolution shows that the decision was correct.