Human factors and ergonomics research focuses on questions pertaining to the design of devices, systems, and procedures with the goal of making sure that they are well suited to human use and focuses on studies of the interaction of people with simple and complex systems and machines. Problem areas studied include the allocation of function to people and machines, person-system interface design, accident prevention, risk assessment, human performance under various types of stress, crisis management, search and rescue operations, decision aiding, the training and coordination of teams, and negotiation and conflict resolution, among many others. Much human factors and ergonomics work has been directed at responding to accidents (train wrecks, airplane crashes, nuclear plant mishaps) and natural disasters (hurricanes, earthquakes, floods). Although most of this work has not been motivated by the reality of terrorism or, in particular, by the attacks of 9/11, much of it is relevant to one or another aspect of terrorism in its various manifestations, and human factors and ergonomics researchers are increasingly making the connection. The purpose of this article is to illustrate this relevance by noting a few studies, from among the many that could be cited, that have implications for helping to prevent terrorism or for dealing with the effects of terrorist incidents when they occur. (Contains 2 footnotes.)