Can researchers, interested in novel ways to assess HIV seroprevalence among populations which are otherwise hidden, collect condoms that have been discarded on the ground in a public sex environment and test them for HIV? Does the Code of Federal Regulations address this question, and if not, what areas of research ethics might provide guidance to an IRB considering such a study? These questions arose as part of a preliminary study to test the feasibility of collecting discarded condoms from a (...) public sex environment in Massachusetts, and testing contained semen for HIV. Although the methodology of this study is somewhat unusual, the questions raised are not. Researchers, who wish to use other types of abandoned samples such as discarded syringes, hair or saliva samples, or even excess biological samples, commonly confront similar issues, and the analysis utilized here could guide design and review of other studies. (shrink)