A 65-year-old, G 3 , P 3 woman referred to gynaecology clinic due to sensation of fullness in the pelvis and a palpable mass in the abdomen since 2 weeks. She had a medical history of osteoarthritis, hypertension and non-insulin-dependent diabetes mellitus. The patient's body mass index was 36 kg/m 2 . Physical examination revealed a large palpable, relatively mobile, non-tender mass in the pelvic region. Ultrasound demonstrated a loculated heterogeneous, cystic mass in pelvis and mild free fluid in the Pouch of Douglas. The lesion had mixed echogenicity with hypo echoic and hyper echoic components, contained solid parts within distinct margins, and were 18cm×15cm×12cm in size. Computed tomography was performed because the lesion extended beyond the pelvis [Table/ Fig-1]. Computed tomography showed a large complex, well-circumscribed mass measuring 18 cm in the largest transverse diameter occupying the pelvis. Her CA-125 levels were 36U/L. Based on the clinical findings and imaging studies malignancy was highly probable, so the patient was prepared for surgery. The patient underwent an exploratory midline laparotomy from above the umbilicus to the symphysis pubis. At surgery, Malignant Mixed Mullerian Tumour of the Ovary (OMMMT), also referred to as carcinosarcoma is a very rare tumour accounting for less than 1% of all ovarian cancers. Due to the rarity of OMMMT, little is known about the disease course and outcome of women with these tumours. It is important to evaluate because of its aggressive behaviour with extremely unfavourable prognosis. These tumours are composed of both malignant epithelial and mesenchymal elements. Current data in the literature is still limited to small case series and case reports, therefore, its optimal treatment is somewhat controversial. In the current report, we introduce a case of OMMMT which was successfully treated with Platinum-based combination chemotherapy after optimal cytoreductive surgery. The clinical manifestations, pathologic characteristics, diagnosis and management of these tumours are reviewed here. Although the most effective treatment is currently unknown, optimal cytoreductive surgery and platinum-based chemotherapy appears to improve the outcomes. Despite the aggressive nature of this tumour and its poor response to the treatment, management works best when cancer is found early. The stage of the disease is the most important prognostic factor. Therefore, the crucial question is how to diagnose the cancer at earlier stages rather than seeking the optimal treatment.keywords: Cytoreductive surgery, Ovarian neoplasms, Platinum-based chemotherapy the pelvic and abdominal organs were closely inspected. The tumour originated from the left ovary and abdominal ascites was noted. The gross appearance of the tumour was predominantly solid and lobulated mass, with varying degrees of haemorrhage and necrosis. We found that no organ was infiltrated, and the right ovary was atrophied. Peritoneal washings were obtained. Frozen section revealed a malignant tumour. The patient...