Ovarian cancer ranks 5th among the most common gynecologic cancers and causes the highest mortality in females. Here, we discuss the role of a group of natural products that are being used in treatment and prevention of a host of cancers including ovarian cancer. Some plants and nutraceuticals and their polyphenolic constituents such as flavones, flavonoids, and antioxidants have shown cytotoxic effects on cancer cells both in vitro and in vivo. While phytochemicals do not harm normal cells, they have been found to be cytotoxic to cancer cells by virtue of inhibition of proliferation and/or induction of apoptosis, making them ideal in cancer therapeutics or as adjunct to conventional treatment regimens.