Mature cystic teratomas (MCT), also known as dermoid cysts, are the most common ovarian germ cell tumors and the most common ovarian neoplasms in patients younger than 20 years. Malignant transformation (MT) is a rare complication of MCTs which may occur in 1–2% of the cases. Squamous cell carcinoma (SCC) is the most frequent histology arising from MCTs and its appearance depends on diverse risk factors such as patient's age, the size of the tumor and levels of serum tumor markers. Diagnosis and treatment constitute a big challenge due to the rarity and the aggressive course of this entity. Adjuvant chemotherapy has a leading role in the treatment of MCT-arising SCC, while the use of radiotherapy or chemoradiation is still under consideration. Herein, we report a case of a post-menopausal woman, presenting with mild symptoms and a large pelvic mass deriving from the left ovary occurring as dermoid cyst. Simultaneously, we review the literature stressing out the prognostic factors and the treatment options for MCT arising SCC according to traditional and new therapy-strategies.