The concept of vulnerability in research derives from a specific set of historical circumstances relating to abuses in biomedical research. Now so many people and groups have been labeled vulnerable that the concept has lost much of its force. In disaster research, participants should not be automatically considered vulnerable unless they are legally designated as such, for example, children. Instead specific aspects of the research should be thoroughly examined. Examples are the potential for the participants to be pressured to participate in several protocols, political or social turmoil surrounding the disaster, and cognitive impairments or mental health problems. In addition to a careful consent process, there should be procedures in place to provide assistance to participants who experience serious distress.