High-output heart failure is an important cause of heart failure that is associated with increased mortality, and most frequently caused by obesity, arteriovenous shunts, and liver disease. However, high-output HF caused by a neoplasm-related arteriovenous fistula in adults is uncommon. We report a case of high-output HF caused by massive arteriovenous fistula shunting associated with suspicious recurrent pelvic cellular leiomyoma. Echocardiography played an essential rale in identification of high-output HF and different etiologies of it by taking concern of stroke volume, cardiac output, cardiac index.