We are pleased to present this Special Issue of the International Journal of Molecular Sciences, entitled “Ovarian Cancer: Advances in Pathophysiology and Therapies”. Ovarian cancer is a gynecologic tumor with high mortality rate. The high lethality of this tumor is mainly due to the fact that it is often diagnosed at an advanced stage of disease [1]. Primary or acquired chemoresistance is a challenge for the management of most malignancies, including ovarian cancer [1–5]. The occurrence of chemoresistance significantly worsens the outcome of ovarian cancer. In fact, although platinum-based drugs (eg, cisplatin, carboplatin and oxaliplatin) and paclitaxel show significant efficiency at the beginning of treatment, many patients relapse within 18 months due to the occurrence of chemoresistance [1, 4].