This article discusses the ethical responsibilities of biomedical researchers to prevent bioterrorism, including duties related to research, publication, editorial review, public education, expert opinion, advocacy, and reporting suspicious activity. Since actions taken to avert bioterrorism may also undermine important scientific norms, such as openness, freedom, and collegiality, and individual rights, such as privacy, biomedical scientists may encounter ethical dilemmas and problems when they consider taking steps against terrorism. This article proposes some policies and recommendations that attempt to strike a fair and reasonable balance between protecting scientific norms and individual rights and promoting national and international security. This article articulates policies and recommendations that will help ensure that the norms that govern biomedical research and individual rights are not casualties in the struggle against terrorism. Drug Dev Res 63: 121-133, 2005.