Scientists and ethicists often speak of subjects as partners in research, but the reality is quite different. Experienced subjects are rarely appointed to the committees that create guidelines for ethical research or the committees that review individual studies to determine whether they meet ethical and regulatory standards. Yet experienced research subjects can make valuable contributions to research ethics. People who have been in studies know facts about the experience that others may overlook. Their experience as subjects gives them special insights into ethics too. Experienced subjects know about problems that can lead people to refuse to join studies or to drop out before studies are complete. A large body of work describes the perceptions and viewpoints of people who have participated in research, but experts rarely use this material to guide improvements in human subject protection. Although subjects have the power to decide whether to participate in a study, they have little control over anything else that goes on in research. Silent Partners moves research subjects to the forefront, examining what research participation is like for healthy volunteers and patients and explaining why subjects’ voices should influence research ethics. Silent Partners shows how experienced research subjects can become real—not just symbolic—partners in research.