Primary cardiac tumors are rare and only a quarter of them are malignant with the vast majority being angiosarcomas. Prognosis of cardiac angiosarcoma is very poor, with median survival of less than 1 year. Patients with complete surgical resection of tumor might have longer survival, but it is feasible only in absence of metastasis. However, metastatic cardiac angiosarcoma via hematogenous routes to the lungs, bones and liver are not unusual. Because of rarity of cardiac angiosarcoma, the literature regarding with its metastases demonstrated on FDG PET/CT is only anecdotal. Herein, we described the PET/CT features of multiple extracardiac FDG-avid metastases in a case of cardiac tumor, misdiagnosed as hemangioma after initial resection but finally revised as angiosarcoma when metastasis became evident within several weeks post-operation. Also because of disseminated metastases and expected poor survival, the patient opted not further treated. Our experience with this case suggests that the regular use of FDG PET/CT may provide not only additional but essential information to facilitate a correct diagnosis of cardiac tumor and can avoid medical malpractice.