As scientists target communities for research into the etiology, especially the genetic determinants of common diseases, there have been calls for the protection of communities. This paper identifies the distinct characteristics of aboriginal communities and their implications for research in these communities. It also contends that the framework in the Belmont Report is inadequate in this context and suggests a fourth principle of respect for communities. To explore how such a principle might be specified and operationalized, it reviews existing guidelines for protecting aboriginal communities and points out problems with these guidelines and areas for further work.