A giant abdominal tumor can exert a mass effect on surrounding structures. We report here a 34-year-old single female who presented with an increased abdominal girth and was subsequently found to have a giant abdominal mass. Large volume aspiration (85 L) at a slow rate (1 L/min) was initially performed before surgical resection to prevent the development of severe clinical hypotension after large volume aspiration. The patient underwent left salpingo-oophorectomy. Histology revealed a serous cystadenoma of the ovary. Systemic hemodynamics were sequentially measured during the perioperative period. The patient is now well.