Intravenous leiomyomatosis(IVL), showing unusual growth patterns of uterine leiomyoma, is a rare neoplasm characterized by intravascular proliferation of a histologically benign-looking smooth muscle cell tumor mass, but not invading the tissue. To date, less than 300 cases have been reported and fewer than 100 cases with cardiac involvement. Imaging characteristics of IVL are still not clear so it is usually misdiagnosed before surgery. A 36-year-old woman, who had undergone hysterectomy due to hysteromyoma, presented with shortness of breath after activities. Imaging showed IVL with mass involvement of the left ovarian vein, left renal vein, left external and common iliac vein, as well as within the inferior vena cava(IVC), extending into the right atrium. The operation demonstrated that the mass had no stalk and had welldemarcated borders with the wall of the right atrium and IVC. The patient underwent a one-stage combined multidisciplinary thoraco-abdominal operation under general anesthetic. Subsequently, the pathology report confirmed IVL. IVL should be considered in a female patient presenting with an extensive mass in the right side of the heart. Imaging technology, such as echocardiogram, contrast-enhanced computed tomography and magnetic resonance imaging, can provide important information to reveal the mass, the range and path of the lesion, and relates to the surgical plan decision. Consequently, perfect and exact image examination is very necessary pre-operation. Intravenous proliferation of a histologically benign-looking smooth muscle cell tumor mass, but not invading the tissue. To date, less than 300 cases have been reported and fewer than 100 cases with cardiac involvement. Imaging characteristics of IVL are still not clear so it is usually misdiagnosed before surgery. A 36-year-old woman, who had undergone hysterectomy due to hysteromyoma, presented with shortness of breath after activities. Imaging showed IVL with mass involvement of the left ovarian vein, left renal vein, left external and common iliac vein, as well as within the inferior vena cava (IVC), extending into the right atrium. The operation demonstrated that the mass had no stalk and had welldemarcated borders with the wall of the right atrium and IVC. The patient underwent a one-stage combined multidisciplinary thoraco-abdominal operation under general The technology of the pathology report confirmed IVL. IVL should be considered in a female patient presenting with an extensive mass in the right side of the heart. Imaging technology, such as echocardiogram, contrast-enhanced computed tomography and magnetic resonance imaging, can provide important information to reveal the mass, the range and path of the lesion, and related to the surgical plan decision.