The President's Council on Bioethics, headed by Leon Kass, was created by President George W. Bush to advise the President on issues of ethical import raised by advances in biomedical science. Between 2002 and 2004, members of the Council from diverse disciplines addressed topics such as human cloning, stem cell research, assisted reproduction, and medical interventions intended to enhance human capability or appearance. This article provides background on the Council and reviews its published reports. It also considers key definitions and distinctions, specific recommendations of the Council, and positions articulated by members who contributed to the development of its reports.