Leiomyoma is a benign tumour composed mainly of smooth muscle cells. It contains varying amount of fibrous connective tissues. Parasitic leiomyoma is a rare manifestation of uterine leiomyoma defined as a pedunculated subserosal fibroid that undergoes torsion and detaches from the uterus. We are reporting a case of parasitic leiomyoma in a 55 Y/O female patient that had already given her consent for the case to be published. She presented with increased abdominal girth since 6 months and body weight and consulting for possible bariatric surgery 1 month prior to presentation. Ultrasonography revealed a large heterogeneous mass starting from the pelvic region to the middle and upper abdomen of more than 37 cm compatible with an adnexal mass. On abdominopelvic MRI: presence of an enlarged heterogeneous mass that seems taking its origin from the right ovary, an exploratory laparotomy was performed. Identification and complete excision of a huge mass of cystic and solid component adherent to the uterus and the mesentery of the small bowel. Histopathologically mass was confirmed as a hyelanized leiomyoma with a focal necrobiosis with no signs of malignity. Parasitic leiomyomas are rare tumors. Imaging modalities help in diagnosis but not always. The definitive treatment is surgical excision, presenting this case due to its rarity and diagnostic difficulties posed.