Intravenous leiomyomatosis was diagnosed in 3 women of reproductive age (35-37 years of age). The tumor located in the uterus or its broad ligament. Histologically, the tumor is represented by intravenous smooth muscle cells. The discussion covers histogenesis of the disease which can be associated with disseminated peritoneal leiomyomatosis, uterine leiomyoma, diffuse pulmonary leiomyomatosis. Intravenous leiomyomatosis is believed to be of tumor origin and to arise in hormonal disturbances.