Massive ovarian edema is a rare clinical entity, posing a significant clinical challenge as it can be easily mistaken for neoplasm. Our case was a 20-year-old young woman who presented with a self-limiting episode of abdominal pain along with large solid pelvis mass. On physical examination, she had abdominal tenderness with guarding. Ultrasound examination revealed large solid ovarian mass with moderate ascites. With the diagnosis of ovarian neoplasm, laparotomy was performed, and intraoperative frozen section excluded malignancy with differentials suggesting of fibromatosis/massive ovarian edema. The patient underwent unilateral salpingo-oophorectomy. Histopathological examination confirmed the diagnosis of massive ovarian edema. Massive ovarian edema should be suspected in women at the fertility age range with solid enlargement of the ovary so that these young patients can be treated conservatively where fertility preservation is mandatory.