Comparative effectiveness research (CER) has been promoted as a way to improve the translation gap between clinical research and everyday clinical practice as well as to deliver more cost-effective health care. CER will account for a significant portion of funding allocated by the US government for health care research. Oncology has a rich history of improving clinical outcomes and advancing research through randomized controlled trials (RCTs). In this article, we review the role of RCTs in achieving the goals of CER, with particular emphasis on the role of publicly funded clinical trials.