This literature review examines the phenomenon of lone wolf terrorism. There seem to be some important factors that contribute to an individual’s deciding to become a lone wolf terrorist instead of joining a larger terrorist group or network. Although there seems to be consensus about terrorists being psychologically stable, it is likely that some lone wolf terrorists could be diagnosed with various forms of psychopathology. Also, lone wolf terrorism is often preceded by a personal event linked to the upcoming terrorist act – something that has made the political personal. Strong reciprocity and group identification are other factors that could contribute to a person becoming a lone wolf terrorist. But to what extent these factors differ in lone wolf and group terrorism is unclear. Another important variable is a more general pattern of acting alone, as well as being socially isolated. Research on lone wolves in a variety of other contexts reveals that these individuals are less likely to trust others to do their job properly. This could also be the case in lone wolf terrorism.