There is mounting evidence that the immune system plays an important role in the development and growth of gynecologic malignancies, and preliminary studies show activity of immune checkpoint inhibitors in ovarian, endometrial, and cervix cancer. In this review, we outline the completed trials of immune checkpoint blockade in the treatment of gynecologic malignancies. In addition, we review the ongoing trials in each disease site. The questions of which patients will benefit from immune checkpoint inhibitors and when immune checkpoint inhibitors should be incorporated into the treatment of gynecologic malignancies continue to be largely unanswered. As preclinical and clinical data emerge regarding predictive markers for response and resistance to immune checkpoint inhibitors, rational combination treatment strategies will help to further develop this emerging field in the treatment of gynecologic malignancies.