Intravenous leiomyomatosis is a rare neoplastic condition characterized by the benign intravascular proliferation of smooth muscle cells originating from either the uterine venous wall or a uterine leiomyoma. In the present report, we describe the case of a 45-year-old woman without a history of gynaecological surgeries, who was referred to our institution due to repeated syncopal attacks. Computed tomography indicated the presence of an intravenous leiomyoma originating from the uterus and extending to the inferior vena cava, right atrium, and right ventricle. The patient was successfully treated by cardiotomy, which was performed under hypothermic circulatory arrest, and laparotomy in a single-stage operation. She continued to recover and did not exhibit any recurrence at the 10-month follow-up.