Diffuse uterine leiomyomatosis is a rare benign entity in gynecology, with only 30 worldwide reports. Its most frequent complications are dissemination into vena cava, cardiac obstruction (right cavities and valves), and diffuse pelvic invasion. We report a case of a 40 years old female with history of pelvic mass resection. During surgery it was found a large abdominal-pelvic mass diffusely invading uterine body, and round and infundibulum-pelvic ligaments. This mass extends itself out of pelvis until aorto-abdominal bifurcation, and has gummatous, elastic, and highly bleeding consistency. Histopathologic report was intravenous leiomyomatosis with benign smooth muscular fibers infiltrating adjacent structures. Its origin was uterine tissue, but it invades, adjacently, all reproductive annexes deforming them anatomy. Its infiltrative quality confers a technical difficulty to surgeon, so he or she will need a multidisciplinary team to establish its treatment.