Interesting and important ethical questions confront researchers, regulators, institutional review boards, support personnel, and research participants committed to the ethical conduct of human subjects research at all stages of research. Questions encompass - but are not limited to - study design, enrolling participants, balancing the clinical needs of participants against the research agenda, ending trials, discharging post-trial obligations, and resolving conflicts. Straightforward solutions to these types of questions are often not found in regulations, ethics codes, or the bioethics literature. These resources may leave room for interpretation, offer conflicting guidance, or simply fail to address particular questions. Ethics consultation, which has been offered in clinical care settings with regularity since the 1980s, has since the turn of the century increasingly been sought in the clinical research context. Because there has only lately been recognition that ethics consultants can play a valuable role helping the research community conduct research in the most ethically informed way, there are many open questions in the field of research ethics consultation including the appropriate role of consultants and the best methods of consultation. The Clinical Center Bioethics Consultation Service has been serving the NIH community of researchers, administrators, healthcare providers, and research participants for more than a decade, conducting nearly 1,000 consultations in that time. In this book, members of the Bioethics Consultation Service reflect on this long track-record and unparalleled range of research ethics consultations to share a collection of their most interesting and informative research ethics consultations and to start a dialogue on remaining open questions. Although the NIH experience is unique, this book focuses on cases - and associated lessons - that are generalizable and valuable for the entire clinical research community. This book will be valuable to ethics consultants, clinical investigators, students and teachers, and others desiring insight into clinical research ethics and ethics consultation.