The HIV/aids pandemic has brought global attention to the ethical challenges of conducting research involving socially vulnerable participants. Such challenges require not only ethical deliberation but also an empirical evidentiary basis for research ethics policies and practices. This need has been addressed through the Fordham University HIV and Drug Abuse Prevention Research Ethics Institute, a National Institute on Drug Abuse–funded program that trains and funds early career scientists in conducting research on HIV/drug abuse research ethics. This article describes the ethical (...) framework guiding Institute training and introduces readers to six empirical articles in this special issue that illuminate and help foster the responsible conduct of research. (shrink)