There is growing recognition that the United States' clinical trials enterprise (CTE) faces great challenges. There is a gap between what is desired - where medical care is provided solely based on high quality evidence - and the reality - where there is limited capacity to generate timely and practical evidence for drug development and to support medical treatment decisions. With the need for transforming the CTE in the U.S. becoming more pressing, the IOM Forum on Drug Discovery, Development, and Translation held a two-day workshop in November 2011, bringing together leaders in research and health care. The workshop focused on how to transform the CTE and discussed a vision to make the enterprise more efficient, effective, and fully integrated into the health care system. Key issue areas addressed at the workshop included: the development of a robust clinical trials workforce, the alignment of cultural and financial incentives for clinical trials, and the creation of a sustainable infrastructure to support a transformed CTE. This document summarizes the workshop.