In an era of promising advances in cancer research, there are considerable and even alarming gaps in the fundamental knowledge and understanding of ovarian cancer. Researchers now know that ovarian cancer is not a single disease-several distinct subtypes exist with different origins, risk factors, genetic mutations, biological behaviors, and prognoses. However, persistent questions have impeded progress toward improving the prevention, early detection, treatment, and management of ovarian cancers. Failure to significantly improve morbidity and mortality during the past several decades is likely due to several factors, including the lack of research being performed by specific disease subtype, lack of definitive knowledge of the cell of origin and disease progression, and incomplete understanding of genetic and non-genetic risk factors. Ovarian Cancers examines the state of the science in ovarian cancer research, identifies key gaps in the evidence base and the challenges to addressing those gaps, considers opportunities for advancing ovarian cancer research, and examines avenues for translation and dissemination of new findings and communication of new information to patients and others. This study makes recommendations for public- and private-sector efforts that could facilitate progress in reducing the incidence of morbidity and mortality from ovarian cancers.